Add test for ArgsManager::GetChainName
Add test for ArgsManager::GetChainName

There was some test coverage previously, but it was limited and didn't test
conflicting and negated arguments.

nikkitan/bitcoin,ajtowns/bitcoin,namecoin/namecoin-core,midnightmagic/bitcoin,n1bor/bitcoin,tjps/bitcoin,litecoin-project/litecoin,dscotese/bitcoin,AkioNak/bitcoin,JeremyRubin/bitcoin,namecoin/namecoin-core,FeatherCoin/Feathercoin,fujicoin/fujicoin,alecalve/bitcoin,wellenreiter01/Feathercoin,bitcoinsSG/bitcoin,Sjors/bitcoin,jtimon/bitcoin,tecnovert/particl-core,fujicoin/fujicoin,gjhiggins/vcoincore,bitcoin/bitcoin,MarcoFalke/bitcoin,jonasschnelli/bitcoin,EthanHeilman/bitcoin,prusnak/bitcoin,mm-s/bitcoin,jonasschnelli/bitcoin,pataquets/namecoin-core,cdecker/bitcoin,fanquake/bitcoin,domob1812/bitcoin,jamesob/bitcoin,tecnovert/particl-core,prusnak/bitcoin,jtimon/bitcoin,vertcoin/vertcoin,jamesob/bitcoin,anditto/bitcoin,lateminer/bitcoin,rnicoll/bitcoin,domob1812/bitcoin,prusnak/bitcoin,Xekyo/bitcoin,n1bor/bitcoin,ElementsProject/elements,kallewoof/bitcoin,jlopp/statoshi,yenliangl/bitcoin,alecalve/bitcoin,monacoinproject/monacoin,MeshCollider/bitcoin,DigitalPandacoin/pandacoin,mruddy/bitcoin,mitchellcash/bitcoin,rnicoll/bitcoin,bitcoinknots/bitcoin,anditto/bitcoin,MeshCollider/bitcoin,FeatherCoin/Feathercoin,jtimon/bitcoin,ahmedbodi/vertcoin,Sjors/bitcoin,GroestlCoin/bitcoin,cdecker/bitcoin,jambolo/bitcoin,CryptArc/bitcoin,pataquets/namecoin-core,particl/particl-core,DigitalPandacoin/pandacoin,GroestlCoin/bitcoin,domob1812/namecore,lateminer/bitcoin,andreaskern/bitcoin,rnicoll/bitcoin,tecnovert/particl-core,andreaskern/bitcoin,nikkitan/bitcoin,domob1812/namecore,mruddy/bitcoin,sipsorcery/bitcoin,rnicoll/bitcoin,anditto/bitcoin,sstone/bitcoin,lateminer/bitcoin,MeshCollider/bitcoin,mm-s/bitcoin,litecoin-project/litecoin,peercoin/peercoin,JeremyRubin/bitcoin,anditto/bitcoin,jlopp/statoshi,achow101/bitcoin,mitchellcash/bitcoin,AkioNak/bitcoin,particl/particl-core,EthanHeilman/bitcoin,peercoin/peercoin,wellenreiter01/Feathercoin,nikkitan/bitcoin,pstratem/bitcoin,FeatherCoin/Feathercoin,gjhiggins/vcoincore,CryptArc/bitcoin,mitchellcash/bitcoin,bitcoin/bitcoin,FeatherCoin/Feathercoin,EthanHeilman/bitcoin,ElementsProject/elements,domob1812/bitcoin,EthanHeilman/bitcoin,jonasschnelli/bitcoin,namecoin/namecore,pataquets/namecoin-core,n1bor/bitcoin,alecalve/bitcoin,fanquake/bitcoin,andreaskern/bitcoin,instagibbs/bitcoin,Sjors/bitcoin,achow101/bitcoin,namecoin/namecoin-core,sipsorcery/bitcoin,fujicoin/fujicoin,mruddy/bitcoin,domob1812/bitcoin,Xekyo/bitcoin,fanquake/bitcoin,tjps/bitcoin,qtumproject/qtum,monacoinproject/monacoin,fujicoin/fujicoin,litecoin-project/litecoin,FeatherCoin/Feathercoin,qtumproject/qtum,gjhiggins/vcoincore,alecalve/bitcoin,ahmedbodi/vertcoin,dscotese/bitcoin,namecoin/namecore,GroestlCoin/bitcoin,tjps/bitcoin,alecalve/bitcoin,pataquets/namecoin-core,monacoinproject/monacoin,vertcoin/vertcoin,CryptArc/bitcoin,bitcoinsSG/bitcoin,jtimon/bitcoin,CryptArc/bitcoin,tjps/bitcoin,monacoinproject/monacoin,FeatherCoin/Feathercoin,domob1812/bitcoin,lateminer/bitcoin,AkioNak/bitcoin,anditto/bitcoin,kallewoof/bitcoin,prusnak/bitcoin,instagibbs/bitcoin,sstone/bitcoin,pataquets/namecoin-core,cdecker/bitcoin,jnewbery/bitcoin,cdecker/bitcoin,MarcoFalke/bitcoin,sstone/bitcoin,jlopp/statoshi,gjhiggins/vcoincore,bitcoinsSG/bitcoin,tecnovert/particl-core,namecoin/namecoin-core,rnicoll/bitcoin,apoelstra/bitcoin,rnicoll/dogecoin,peercoin/peercoin,jamesob/bitcoin,monacoinproject/monacoin,jambolo/bitcoin,midnightmagic/bitcoin,nikkitan/bitcoin,CryptArc/bitcoin,nikkitan/bitcoin,mitchellcash/bitcoin,GroestlCoin/bitcoin,Sjors/bitcoin,andreaskern/bitcoin,tecnovert/particl-core,Xekyo/bitcoin,sipsorcery/bitcoin,MeshCollider/bitcoin,dscotese/bitcoin,fanquake/bitcoin,cdecker/bitcoin,GroestlCoin/GroestlCoin,ahmedbodi/vertcoin,Xekyo/bitcoin,jnewbery/bitcoin,litecoin-project/litecoin,yenliangl/bitcoin,rnicoll/dogecoin,tjps/bitcoin,tjps/bitcoin,peercoin/peercoin,mruddy/bitcoin,AkioNak/bitcoin,bitcoinsSG/bitcoin,mruddy/bitcoin,wellenreiter01/Feathercoin,MeshCollider/bitcoin,pstratem/bitcoin,DigitalPandacoin/pandacoin,namecoin/namecore,wellenreiter01/Feathercoin,yenliangl/bitcoin,jlopp/statoshi,MarcoFalke/bitcoin,rnicoll/dogecoin,jambolo/bitcoin,Xekyo/bitcoin,apoelstra/bitcoin,jnewbery/bitcoin,ElementsProject/elements,yenliangl/bitcoin,wellenreiter01/Feathercoin,achow101/bitcoin,pstratem/bitcoin,pstratem/bitcoin,yenliangl/bitcoin,instagibbs/bitcoin,AkioNak/bitcoin,pstratem/bitcoin,ajtowns/bitcoin,jamesob/bitcoin,fujicoin/fujicoin,JeremyRubin/bitcoin,mm-s/bitcoin,apoelstra/bitcoin,sstone/bitcoin,MeshCollider/bitcoin,rnicoll/dogecoin,gjhiggins/vcoincore,domob1812/namecore,GroestlCoin/GroestlCoin,practicalswift/bitcoin,apoelstra/bitcoin,mitchellcash/bitcoin,wellenreiter01/Feathercoin,domob1812/namecore,nikkitan/bitcoin,particl/particl-core,ElementsProject/elements,jamesob/bitcoin,practicalswift/bitcoin,midnightmagic/bitcoin,tecnovert/particl-core,practicalswift/bitcoin,GroestlCoin/GroestlCoin,EthanHeilman/bitcoin,pataquets/namecoin-core,ahmedbodi/vertcoin,sstone/bitcoin,EthanHeilman/bitcoin,jlopp/statoshi,jlopp/statoshi,GroestlCoin/bitcoin,namecoin/namecore,mm-s/bitcoin,jtimon/bitcoin,pstratem/bitcoin,fujicoin/fujicoin,particl/particl-core,midnightmagic/bitcoin,n1bor/bitcoin,namecoin/namecore,dscotese/bitcoin,alecalve/bitcoin,practicalswift/bitcoin,mitchellcash/bitcoin,instagibbs/bitcoin,GroestlCoin/bitcoin,ajtowns/bitcoin,bitcoin/bitcoin,prusnak/bitcoin,midnightmagic/bitcoin,ahmedbodi/vertcoin,DigitalPandacoin/pandacoin,dscotese/bitcoin,qtumproject/qtum,kallewoof/bitcoin,rnicoll/dogecoin,apoelstra/bitcoin,n1bor/bitcoin,mm-s/bitcoin,litecoin-project/litecoin,kallewoof/bitcoin,DigitalPandacoin/pandacoin,bitcoin/bitcoin,MarcoFalke/bitcoin,DigitalPandacoin/pandacoin,fanquake/bitcoin,vertcoin/vertcoin,fanquake/bitcoin,ahmedbodi/vertcoin,AkioNak/bitcoin,GroestlCoin/GroestlCoin,andreaskern/bitcoin,qtumproject/qtum,practicalswift/bitcoin,domob1812/namecore,bitcoin/bitcoin,achow101/bitcoin,instagibbs/bitcoin,jonasschnelli/bitcoin,GroestlCoin/GroestlCoin,vertcoin/vertcoin,bitcoin/bitcoin,namecoin/namecoin-core,jtimon/bitcoin,monacoinproject/monacoin,bitcoinknots/bitcoin,jonasschnelli/bitcoin,bitcoinknots/bitcoin,jnewbery/bitcoin,Xekyo/bitcoin,anditto/bitcoin,peercoin/peercoin,ajtowns/bitcoin,jambolo/bitcoin,rnicoll/bitcoin,bitcoinsSG/bitcoin,peercoin/peercoin,achow101/bitcoin,qtumproject/qtum,namecoin/namecore,qtumproject/qtum,apoelstra/bitcoin,domob1812/namecore,ElementsProject/elements,CryptArc/bitcoin,yenliangl/bitcoin,bitcoinknots/bitcoin,namecoin/namecoin-core,andreaskern/bitcoin,particl/particl-core,mm-s/bitcoin,JeremyRubin/bitcoin,litecoin-project/litecoin,kallewoof/bitcoin,cdecker/bitcoin,kallewoof/bitcoin,MarcoFalke/bitcoin,midnightmagic/bitcoin,jnewbery/bitcoin,ajtowns/bitcoin,sipsorcery/bitcoin,instagibbs/bitcoin,bitcoinsSG/bitcoin,dscotese/bitcoin,sipsorcery/bitcoin,particl/particl-core,JeremyRubin/bitcoin,achow101/bitcoin,ajtowns/bitcoin,sstone/bitcoin,vertcoin/vertcoin,JeremyRubin/bitcoin,n1bor/bitcoin,Sjors/bitcoin,vertcoin/vertcoin,lateminer/bitcoin,practicalswift/bitcoin,sipsorcery/bitcoin,jambolo/bitcoin,domob1812/bitcoin,bitcoinknots/bitcoin,MarcoFalke/bitcoin,gjhiggins/vcoincore,GroestlCoin/GroestlCoin,qtumproject/qtum,jamesob/bitcoin,ElementsProject/elements,prusnak/bitcoin,jambolo/bitcoin,mruddy/bitcoin,lateminer/bitcoin