ci/transformers: add baseline checks for test cases

[dvrogozh]

Baseline is set in a python script. Script looks into the results and categorizes test cases as:

• New failures - if detected workflow is marked as failed
• New passes - if detected workflow is marked as failed (since baseline requires an update)
• Skipped flickies - if detected workflow is marked as failed (since baseline requires an update)
• Known failures - these are failing tests knowing to fail per baseline, workflow is marked as passed (if nothing from above detected)

Test cases from above categories are printed into summary.