sonar-audit should check about branches that only have 1 version

[okorach]

In the life of a project, each branch version is supposed to evolve over time. If:

• There is only 1 version in the branch history
• The duration since the first analysis of that branch is long enough (Say 90 days)
• The branch is marked as keep when inactive

The 90 days should be a configurable parameter.

cc @sylvain-combe-sonarsource

[sylvain-combe-sonarsource]

If a branch configured on the Project Version New Code Period setting is checked, the checks can be:

• the version has never evolved (and the branch is old enough)
• no version was set
• the version changed on subsequent analyses too close to one another
• the version changed on a failed Quality Gate

I don't think having the branch marked as 'keep when inactive' makes a difference.