Hikari-ongaku

- Extensions:
- Added the ability to create extensions for ongaku.
- Checker: Checks if a link, contains a video/playlist.
- Fixes:
- player skip: Fixed an issue where the skip function would not work.
- player stop: Added a new function, to stop the current track, via removing it from the guilds session.

- Ongaku -> Client: `ongaku.Ongaku()` has been replaced by `ongaku.Client()`.
- Client:
- create, delete, and fetch player, has been renamed from `client.create_player()` -> `client.player.create()`, for all types.
- `nodes` -> `sessions`: Nodes has been replaced with sessions, to match lavalink.
- Sessions:
- Websocket: It is now handled as a task, and no longer concurrently.
- Manual: The ability to create your own sessions, by whatever methods you want.
- Connection: The connection to the websocket lavalink provides, is now handled as a task, and not directly blocking your code. This also means it can be shutdown.
- Player:
- Exceptions: More cleanly handled, plus, documentation on those exceptions as well.
- Updates: Each time a function is called, the player is actually modified (via any function) the player will be modified to reflect that.
- volume -> set_volume: The reason for this rename, is so that the `volume` is the current volume, and `set_volume` actually sets the volume.
- auto-play: a new feature has been added, called autoplay. (technically, it already existed) but now you can disable (and re-enable) it, and check its status via `player.set_autoplay()` and `player.autoplay`
- Rest changes:
- General Function: All rest actions are no longer scattered across with some containing some error exceptions, and others containing different exceptions, they all will except, in the exact same way.
- Searching: Ongaku no longer handles your queries, with whether or not, they are a url, or a query for youtube, youtube music, or soundcloud.
- RestApi -> RESTClient: `RestApi` has been replaced by `RESTClient` for more consistent naming. (This does not change anything outside of it.)
- Added methods: added `decode_track`, and `decode_tracks` for more search functions.
- Documentation:
- Type checking: There is now type checking for the doc strings, so, they should look similar, with a lot more information packed within them.
- Extensions: New tab added, for extensions, where extensions can be added in the future.

- Filters: Added filters, for the lavalink players, so your able to change different sound effects for the players, like the EQ, Low Pass, Vibrato, and more.
- Requestors: Added the ability to set a requestor to a specific track. When a song is added to the player, you can set a requestor as an optional argument. You can then fetch it via the [track][ongaku.abc.track.Track].
- Auto Nodes: Automatically creates nodes, for each new shard within the hikari bot.