rpc: move-only: consolidate blockchain scan args
rpc: move-only: consolidate blockchain scan args

For later reuse in `scanblocks`.

sipsorcery/bitcoin,bitcoin/bitcoin,lateminer/bitcoin,mruddy/bitcoin,AkioNak/bitcoin,particl/particl-core,bitcoinsSG/bitcoin,bitcoin/bitcoin,AkioNak/bitcoin,tecnovert/particl-core,sipsorcery/bitcoin,fanquake/bitcoin,namecoin/namecoin-core,kallewoof/bitcoin,sstone/bitcoin,tecnovert/particl-core,kallewoof/bitcoin,mruddy/bitcoin,lateminer/bitcoin,namecoin/namecoin-core,mruddy/bitcoin,sipsorcery/bitcoin,particl/particl-core,bitcoin/bitcoin,jambolo/bitcoin,lateminer/bitcoin,sipsorcery/bitcoin,jambolo/bitcoin,sipsorcery/bitcoin,fanquake/bitcoin,particl/particl-core,AkioNak/bitcoin,fanquake/bitcoin,namecoin/namecoin-core,bitcoin/bitcoin,sstone/bitcoin,jambolo/bitcoin,sstone/bitcoin,tecnovert/particl-core,mruddy/bitcoin,lateminer/bitcoin,jambolo/bitcoin,particl/particl-core,sstone/bitcoin,bitcoinsSG/bitcoin,AkioNak/bitcoin,namecoin/namecoin-core,bitcoin/bitcoin,mruddy/bitcoin,sstone/bitcoin,bitcoin/bitcoin,fanquake/bitcoin,jambolo/bitcoin,fanquake/bitcoin,particl/particl-core,kallewoof/bitcoin,mruddy/bitcoin,kallewoof/bitcoin,lateminer/bitcoin,kallewoof/bitcoin,bitcoinsSG/bitcoin,bitcoinsSG/bitcoin,tecnovert/particl-core,particl/particl-core,tecnovert/particl-core,lateminer/bitcoin,bitcoinsSG/bitcoin,kallewoof/bitcoin,jambolo/bitcoin,bitcoinsSG/bitcoin,tecnovert/particl-core,namecoin/namecoin-core,AkioNak/bitcoin,sstone/bitcoin,fanquake/bitcoin,sipsorcery/bitcoin,namecoin/namecoin-core,AkioNak/bitcoin