CheckTransaction (N.f.B: CheckCoinbase, CheckTransactionCommon and CheckRegularTransaction
in our case ) is a context-free function that does not require access to the blockchain
or mempool. Move it from src/consensus/tx_verify in lib_server to a new unit
src/consensus/tx_check in lib_consensus so that it can be called by non-server libraries.
fdf8888b6f0c63e8a4cb1459752625e642d6a4dd (John Newbery)
This is a partial backport of Core PR15638