Reconfigure GitHub workflows to add compilation+tests checks and use specific triggers

[Grouloo]

It would be nice to add the following GitHub workflows and trigger them for new pull-requests:

• Compilation check (tsc command)
• Unit tests check (bun test command). Though, this one can wait until we actually have unit tests

We also don't need to build the Docker image for each new commit, triggering the workflow upon tagging should be enough.

Creating a tag would then mean "this code is ready for production".