Discard old INSTANCE_CHANGE messages

Acceptance criteria

• Tests should be written that confirm that old enough INSTANCE_CHANGE messages are discarded
• Accumulated INSTANCE_CHANGE messages should be discarded based on some configurable timeout
• Also it should be possible to turn of this functionality from config file

Additional notes

• This won't totally prevent incidents like INDY-1903, just reduce probability of such situation
• This can potentially introduce other failure modes
• Most probably this should be turned off when proper fix is delivered
• Main reason why this task exists is because it's one of the simplest and fastest ways to significantly reduce chance of incidents like INDY-1903