SAST execution should raise an error if project directory is empty
If the project dir is empty, SAST will still try all analyzers, leading to an error "No compatible analyzer can be found" (+ exit code 3). While this is technically correct, it's misleading for the user if there's a configuration issue. In this case, the project dir is empty, and we should stop the execution before trying to detect languages with a Project dir is empty, aborting
error.
/cc @bikebilly