Properly Support multi-project repos #4199

Hello, Came across the CodeQL action but it looks like I am not really able to use it effectively as I have a monorepo that has multiple sub-projects.

Main issues:

1. While main syntax of the workflow is capable of being configured to focus on just one sub-project, it is cumbersome to do so.
2. The integration with GitHub (at the project level) simply does not support the practice at all; does not separate per sub-project, but shows an aggregation of all projects

Any way we can get to where this is doable, or am I just not finding how to do this? Example of what I have going here: https://github.com/Epic-Breakfast-Productions/ebp-ci/blob/main/.github/workflows/quarkus-ci-pipeline.yml#L33