[ci] Cleanup and order GHA workflows (#4449)
Github currently [doesn't support creating subfolders](https://github.com/orgs/community/discussions/18055) in `.github/workflows` folder. PR unifies naming in this folder. The idea is that all files ideally should have naming `<stage>-<short_descriptive_name>.yml`. The stage names are taken from gitlab and needed only for logical division. Changes in actions: - `check-licences` runs on self-hosted runners - `check-workspace` and `check-markdown` are moved to `checks-quick.yml` - `test-linux-stable-int` moved to a new file `tests-linux-stable.yml` - `fmt-check.yml` file is removed, formatting is checked in `checks-quick.yml`