net: Set relay in version msg to peers with relay permission

Summary:

Seems odd to set the relay permission in -blocksonly mode and also ask the peer not to relay transactions.

This is a backport of core#26248
Depends on D16795

Test Plan: ninja all check-all

Reviewers: #bitcoin_abc, Fabien

Reviewed By: #bitcoin_abc, Fabien

Differential Revision: https://reviews.bitcoinabc.org/D16796