[Maven][Junit] Add more flexibility on junit plugin

Current situation

There is a junit plugin that only accept specific options. It is not possible to do what we want with it.

If a client want to test his own snapshot, he won't test the last one but something in cache.

Desired outcome

A variable like MAVEN_OPTS but better to update the snapshots and other things. Possibility to add a maven phase/job before or after the run. The fact that we are forced to use only test is a limitation.