[test] Add getblockchaininfo functional test

Summary:

• [test] Add restart_node to BitcoinTestFramework
• [test] Add getblockchaininfo functional test
• Remove bip9_softforks as it is not relevent for ABC

This is a backport of Core PR11370

Test Plan:

./test/functional/test_runner.py

Reviewers: #bitcoin_abc, jasonbcox

Reviewed By: #bitcoin_abc, jasonbcox

Subscribers: teamcity

Differential Revision: https://reviews.bitcoinabc.org/D1940