feat: refactor test bot

[onerandomusername]

closes #246

[shiftinv]

Since this will be using dotenv, test_launcher.py could probably be removed (TestBot.load_all_extensions might have to be updated then).

An env flag to enable debug logs¹ could be cool as well.

¹ something like this, I suppose

if DEBUG:
    logging.basicConfig(
        format="%(asctime)s: [%(levelname)s] (%(threadName)s) %(name)s: %(message)s",
        level=logging.INFO,
    )
    logging.getLogger("disnake").setLevel(logging.DEBUG)

[Victorsitou]

Could you add support for logs in a file? Sometimes I don't like to have logs in my command line.

[EQUENOS]

I suggest moving test bot to another repo

[onerandomusername]

Could you add support for logs in a file? Sometimes I don't like to have logs in my command line.

Added as of https://github.com/DisnakeDev/disnake/pull/247/commits/6f76533f0d1e87edb1296131077c3ff50ae989ec

[EmmmaTech]

Any updates on this?