[wallet] Restore confirmed/conflicted tx check in SubmitMemoryPoolAndRelay() (John Newbery)
[wallet] restore coinbase check in SubmitMemoryPoolAndRelay() (John Newbery)
Pull request description:
These checks don't change mempool acceptance/relay behaviour, but reduce log spam.
https://github.com/bitcoin/bitcoin/pull/16557/files
Backport of Core PR16557