Enhance reliability of backward compatibility test

[jpraynaud]

Why

We want to make the e2e test more robust to support previous versions of the nodes which do not support some new features introduced after their release. The backward compatibility test is quite unreliable whenever a breaking change is introduced.

What

Add a feature activation mechanism in the e2e test to run operations based on the node versions.

How

• Add the --unstable parameter to all the commands of the client in the e2e test
• Create a mapping of new versions (or their range) introduced after the release of node versions which must be compatible
• In the functions that could fail on previous versions of the nodes:
  • Skip the execution of the function and consider it as success
  • Add a warning message stating that the function execution has been skipper

Scenario steps that must changes according to the node version

• update_protocol_parameters: only on leader aggregator for unstable node, for all aggregators on released distribution (2543 and before)