Merge request pipeline modifications/cleanup

Some changes could be done to the MR pipeline:

• Remove job selection-test-processing: this is basically a smoke test for the selection test operating points. I don't think we still need it.
• Run clang-format-check and check-if-branch-is-up-to-date-with-main at the very first in each pipeline. If one forgets to fix the formatting or update to main, these validation jobs often only fail after everything else has been run (which takes approx. 20 minutes). This feedback would be good to have immediately so one does not have to wait so long and then get the unexpected failure.
• move voip-be-on-merge-request from compare to test stage (nitpick)
• Remove upload-selection-BE-log job as it is not no longer needed.