rpc, refactor: Add `getblock_prevout`
rpc, refactor: Add `getblock_prevout`

This change eliminates memory usage spike when compiling with Visual
Studio 2022 (at least in Cirrus CI environment).

Easy to review using
`git diff --color-moved-ws=allow-indentation-change --color-moved=dimmed-zebra`

lateminer/bitcoin,bitcoinsSG/bitcoin,fanquake/bitcoin,fujicoin/fujicoin,AkioNak/bitcoin,kallewoof/bitcoin,bitcoin/bitcoin,sipsorcery/bitcoin,tecnovert/particl-core,mruddy/bitcoin,namecoin/namecore,jambolo/bitcoin,mruddy/bitcoin,namecoin/namecore,sipsorcery/bitcoin,sipsorcery/bitcoin,sstone/bitcoin,particl/particl-core,jamesob/bitcoin,Xekyo/bitcoin,AkioNak/bitcoin,AkioNak/bitcoin,bitcoin/bitcoin,ajtowns/bitcoin,bitcoinsSG/bitcoin,jamesob/bitcoin,particl/particl-core,ajtowns/bitcoin,Xekyo/bitcoin,jambolo/bitcoin,particl/particl-core,namecoin/namecoin-core,tecnovert/particl-core,particl/particl-core,namecoin/namecore,sipsorcery/bitcoin,ajtowns/bitcoin,bitcoinsSG/bitcoin,jamesob/bitcoin,Xekyo/bitcoin,lateminer/bitcoin,kallewoof/bitcoin,jambolo/bitcoin,jambolo/bitcoin,namecoin/namecoin-core,namecoin/namecoin-core,lateminer/bitcoin,particl/particl-core,lateminer/bitcoin,bitcoin/bitcoin,sstone/bitcoin,fujicoin/fujicoin,tecnovert/particl-core,namecoin/namecore,lateminer/bitcoin,kallewoof/bitcoin,fujicoin/fujicoin,bitcoinsSG/bitcoin,sstone/bitcoin,ajtowns/bitcoin,sstone/bitcoin,fanquake/bitcoin,fanquake/bitcoin,Xekyo/bitcoin,tecnovert/particl-core,AkioNak/bitcoin,namecoin/namecore,fujicoin/fujicoin,bitcoinsSG/bitcoin,jambolo/bitcoin,jamesob/bitcoin,particl/particl-core,mruddy/bitcoin,kallewoof/bitcoin,bitcoin/bitcoin,lateminer/bitcoin,sipsorcery/bitcoin,namecoin/namecoin-core,fanquake/bitcoin,jamesob/bitcoin,mruddy/bitcoin,mruddy/bitcoin,Xekyo/bitcoin,ajtowns/bitcoin,fujicoin/fujicoin,kallewoof/bitcoin,kallewoof/bitcoin,jambolo/bitcoin,AkioNak/bitcoin,fanquake/bitcoin,bitcoin/bitcoin,fanquake/bitcoin,sipsorcery/bitcoin,namecoin/namecoin-core,Xekyo/bitcoin,namecoin/namecore,bitcoinsSG/bitcoin,fujicoin/fujicoin,ajtowns/bitcoin,bitcoin/bitcoin,AkioNak/bitcoin,mruddy/bitcoin,tecnovert/particl-core,jamesob/bitcoin,tecnovert/particl-core,sstone/bitcoin,namecoin/namecoin-core,sstone/bitcoin