[test] feefilter during and after IBD

Summary:

This is a followup to #19204 which uses minfeefilter=MAX_MONEY to effectively shut off txrelay, thereby reducing inv traffic, when nodes are in IBD. It was missing a functional test.

Co-authored-by: Jon Atack <jon@atack.com>

This is a backport of core#19423

Test Plan: ninja check-functional

Reviewers: #bitcoin_abc, Fabien

Reviewed By: #bitcoin_abc, Fabien

Differential Revision: https://reviews.bitcoinabc.org/D10014