#11744 Generate coverage report using only GitHub Actions

[adiroiban]

Scope and purpose

Fixes #11744

This tries to replace the functionality of codecov.io

For now, we have both custom coverage report and codecov.io in parallel

I would like to have this used in parallel for some time.

Once we are happy with this code, we can remove codecov.io

This will only fail the PR check on missing diff coverage.

There is no coverage badge with this code... we can look into the badge thing later, but for me the badge is not that important.

The coverate report should be visible inside github step summary