[net/refactor] Remove m_addr_fetch member var from CNode

Summary:
Partial backport (12/19) of core PR19316:
https://github.com/bitcoin/bitcoin/pull/19316/commits/7b322df6296609570e368e5f326979279041c11f

Depends on D8721.

Test Plan:

ninja all check-all

Reviewers: #bitcoin_abc, PiRK

Reviewed By: #bitcoin_abc, PiRK

Differential Revision: https://reviews.bitcoinabc.org/D8722