test: add functional test for non-standard txs with too large scriptSig

Summary:

A transaction is rejected by the mempool with reason "scriptsig-size" if any of
the inputs' scriptSig is larger than 1650 bytes.

This is a backport of Core PR17532

Test Plan: ninja && test/functional/test_runner.py mempool_accept

Reviewers: O1 Bitcoin ABC, #bitcoin_abc, Fabien

Reviewed By: O1 Bitcoin ABC, #bitcoin_abc, Fabien

Differential Revision: https://reviews.bitcoinabc.org/D8269