…wit outputs

We will use this helper in later commits to detect witness stripping without having
to execute every input Script three times in a row.

Github-Pull: bitcoin#33105
Rebased-From: 2907b58

Since it was introduced in 4eb5155 (bitcoin#18044), the detection of a
stripped witness relies on running the Script checks 3 times. In the worst case, this consists in
running Script validation 3 times for every single input.

Detection of a stripped witness is necessary because in this case wtxid==txid, and the transaction's
wtxid must not be added to the reject filter or it could allow a malicious peer to interfere with
txid-based orphan resolution as used in 1p1c package relay.

However it is not necessary to run Script validation to detect a stripped witness (much less so
doing it 3 times in a row). There are 3 types of witness program: defined program types (Taproot,
P2WPKH, P2WSH), undefined types, and the Pay-to-anchor carve-out.

For defined program types, Script validation with an empty witness will always fail (by consensus).
For undefined program types, Script validation is always going to fail regardless of the witness (by
standardness). For P2A, an empty witness is never going to lead to a failure.

Therefore it holds that we can always detect a stripped witness without re-running Script validation.
However this might lead to more "false positives" (cases where we return witness stripping for an
otherwise invalid transaction) than the existing implementation. For instance a transaction with one
P2PKH input with an invalid signature and one P2WPKH input with its witness stripped. The existing
implementation would treat it as consensus invalid while the implementation in this commit would
always consider it witness stripped.

Github-Pull: bitcoin#33105
Rebased-From: 27aefac

Github-Pull: bitcoin#32473
Rebased-From: 9014d40

Github-Pull: bitcoin#32473
Rebased-From: 8f3ddb0

Github-Pull: bitcoin#32473
Rebased-From: 92af9f7

Github-Pull: bitcoin#32473
Rebased-From: b221aa8

Github-Pull: bitcoin#32473
Rebased-From: 8395027

Do not discourage nodes even when they send us consensus invalid
transactions.

Because we do not discourage nodes for transactions we consider
non-standard, we don't get any DoS protection from this check in
adversarial scenarios, so remove the check entirely both to simplify the
code and reduce the risk of splitting the network due to changes in tx
relay policy.

NOTE: Backport required additional adjustment in test/functional/p2p_invalid_tx

Github-Pull: bitcoin#33050
Rebased-From: 266dd0e

Previously, we would check failing input scripts twice when considering
a transaction for the mempool, in order to distinguish policy failures
from consensus failures. This allowed us both to provide a different
error message and to discourage peers for consensus failures. Because we
are no longer discouraging peers for consensus failures during tx relay,
and because checking a script can be expensive, only do this once.

Also renames non-mandatory-script-verify-flag error to
mempool-script-verify-flag-failed.

NOTE: Backport required additional adjustment in test/functional/feature_block

Github-Pull: bitcoin#33050
Rebased-From: b29ae9e

Github-Pull: bitcoin#33050
Rebased-From: 876dbdf