Add PyLav support

You can use core-pylav and extra-pylav in place of core-audio/extra-audio to use PyLav instead of the Audio cog.
Be sure to read the official setup guide before doing that though: https://github.com/PyLav/PyLav/blob/master/SETUP.md#pylavyaml-setup-docker

Hotfix PyLav installation

root/app/functions/pylav_setup.py

@@ -237,7 +237,7 @@ def update_existing_commit(commit_hash: str) -> None:
         # This script was called outside a docker container or the docker container is not a pylav image
         log.info("Skipping PyLav setup and update")
         sys.exit(0)
-    for folder in (DownloaderLibFolder, RepoManagerRepoFolder, CogManagerCogFolder):
+    for folder in (DATA_FOLDER, DownloaderLibFolder, RepoManagerRepoFolder, CogManagerCogFolder):
         if not folder.exists():
             folder.mkdir(parents=True, mode=0o776)
     if not DEV_PYLAV_COGS: