Remove direct bitcoin calls from qt/peertablemodel.cpp

Summary:
Partial backport of Core PR 102444
https://github.com/bitcoin/bitcoin/pull/10244/commits/e0b66a3b7c5d3a079636d61fcf611bb6b36c7bc1
Progress towards T417
Depends on D2819

Test Plan:
make check
ninja
bitcoin-qt # sanity checking; check peer table in debug window

Reviewers: deadalnix, Fabien, #bitcoin_abc

Reviewed By: deadalnix, Fabien, #bitcoin_abc

Differential Revision: https://reviews.bitcoinabc.org/D2821