Compared with previous bans, the following changes are made:

• Txn with empty vin/vout or null prevouts move from 10 DoS points to 100.
• Loose transactions with a dependency loop now result in a ban instead of 10 DoS points.
• Many pre-segwit soft-fork errors now result in a ban. Note: Transactions that violate soft-fork script flags since P2SH do not generally result in a ban. Also, banning behavior for invalid blocks is dependent on whether the node is validating with multiple script check threads, due to a long- standing bug. That inconsistency is still present after this commit.
• Proof of work failure moves from 50 DoS points to a ban.
• Blocks with timestamps under MTP now result in a ban, blocks too far in the future continue to *not* result in a ban.
• Inclusion of non-final transactions in a block now results in a ban instead of 10 DoS points.

Co-authored-by: Anthony Towns <aj@erisian.com.au>

This is a partial backport of Core PR15141 : https://github.com/bitcoin/bitcoin/pull/15141/commits/7b999103e21509e1c2dec10f68e48744ffe90f55

Depends on D6684