Merge #8393: Support for compact blocks together with segwit

27acfc1 [qa] Update p2p-compactblocks.py for compactblocks v2 (Suhas Daftuar)
422fac6 [qa] Add support for compactblocks v2 to mininode (Suhas Daftuar)
f5b9b8f [qa] Fix bug in mininode witness deserialization (Suhas Daftuar)
6aa28ab Use cmpctblock type 2 for segwit-enabled transfer (Pieter Wuille)
be7555f Fix overly-prescriptive p2p-segwit test for new fetch logic (Matt Corallo)
06128da Make GetFetchFlags always request witness objects from witness peers (Matt Corallo)