[tests] [qt] Add tests for address book manipulation via EditAddressDialog

Summary:
Also modifies corresponding QT code to allow for use within test cases.

This is a partial backport of Core PR12830 : https://github.com/bitcoin/bitcoin/pull/12830/commits/5109fc4a9cb2cbd73c33197fb9129e1413ab051b

Depends on D3669, D3666 and D3665

Test Plan:

make check
./test/functional/test_runner.py

Reviewers: #bitcoin_abc, jasonbcox

Reviewed By: #bitcoin_abc, jasonbcox

Subscribers: jasonbcox

Differential Revision: https://reviews.bitcoinabc.org/D3670