Allow running unit and functional tests with the -fae maven option on PR checks

The current build for the nuxeo repository does not use the "-fae" (fail at end) option in maven, which could be useful to get a complete status on all tests, instead of stopping at the first failure.

Since we want to fail fast, this option should not be used by default, but could be set on the build by adding a specific "failatend" label on the PR.