net processing: Add support for getcfilters

Summary:

Support getcfilters requests when -peerblockfilters is set.

Does not advertise compact filter support in version messages.

Backport of core PR19044.

Depends on D8465.

Test Plan:

ninja all check-all

Reviewers: #bitcoin_abc, deadalnix

Reviewed By: #bitcoin_abc, deadalnix

Differential Revision: https://reviews.bitcoinabc.org/D8469