test: Extend functional tests for addr relay

Summary:

This extends the functional test p2p_addr_relay.py.
It adds test coverage for address relay involving outbound peers, tests for both outgoing and incoming GETADDR requests and tests for -blocksonly mode.

Backport of core#21707, core#21785 (fix intermittent failure in the test) and core#22306 (improvements to p2p_addr_relay.py, also fixes an intermittent issue).

Note to reviewers: you can look at the file after #22306 to get the final version of the test.

Depends on D10860.

Ref T1696.

Test Plan:

ninja check-functional

Reviewers: #bitcoin_abc, PiRK

Reviewed By: #bitcoin_abc, PiRK

Subscribers: PiRK

Maniphest Tasks: T1696

Differential Revision: https://reviews.bitcoinabc.org/D10861