backport: merge bitcoin#15596, #21207, partial bitcoin#22155 (wallet refactoring)#6543

Merged

PastaPastaPasta merged 3 commits intodashpay:developfrom

kwvg:wallet_refacs

Feb 6, 2025

Commits on Feb 6, 2025

merge bitcoin#15596: Ignore sendmany::minconf as dummy value
kwvg
committed
partial bitcoin#22155: Add test for subtract fee from recipient behavior
kwvg
committed
merge bitcoin#21207: CWallet transaction code out of wallet.cpp/.h
kwvg
committed