Merge ui_rm_head into one workflow file using matrix

[thehejik]

It should be possible to merge all 3 head-2.x workflow files into one workflow file by using matrix, so far we are using just 2 various variables (rancher_version and upstream_cluster_version).

Also it shouldn't prevent us to use an extra variables if we need them let say for disabling specific tests for 2.9 by following this document https://docs.github.com/en/actions/using-jobs/using-a-matrix-for-your-jobs#example-expanding-configurations

Also update description of qase_run_id there and provide hint for possible values like 'auto'/'none'/existing_qase_id#).

[thehejik]

The change lives here main...matrix

But there is a problem with status badges which should be addressed first ideally without involving 3rd party action. The default gh badge supports only overall status for the entire workflow but not its sub-jobs.

I was thinking about involving gh-pages on this repo and using https://img.shields.io/badge/MYJOB-STATUS-green where I could dynamically generate a simple html with proper state of last main run.

Or similarly we could save ci results into last-results.json file on gh pages in our gh project after finishing main job on schedule and then use something like https://shields.io/badges/dynamic-json-badge

[thehejik]

Reverted due to problems with badges. We will have to find a better way than 40ants service.