Merge: ci: basic bench with old branch

This adds a job where a basic execution is compared against origin/master is order to catch important time or space regressions. Because the test machine is shared with many jobs, the results are not that reliable and some additional checks by the integrator might be required.

However, the script can help developers to do a basic check to document their PR.

Pull-Request: #2739
Reviewed-by: Alexis Laferrière <alexis.laf@xymus.net>