Make repo short name part of the config

[gpsaggese]

We have a weird hacky logic to find out the short name of the repo (which is used for the naming of the bugs and other small things)

@functools.lru_cache()
def _get_repo_short_to_full_name(include_host_name: bool) -> Dict[str, str]:

We should rip off that crap and create a var for the short name in the config