Summary:
I've refactored the integration test for HA so we can reuse the common
parts like starting/stopping workers.
I've also added a test that triggers the log compaction and it checks that the
snapshot that has been transferred is the same as the origin one.
Reviewers: ipaljak
Reviewed By: ipaljak
Subscribers: mferencevic, pullbot
Differential Revision: https://phabricator.memgraph.io/D1847
