Add Twitch, error handling, revokation changes, etc

Fix connection update visibilty dying when given boolean

Update todo in access-token route

Refreshable connections, refactoring, access-token endpoint ...

- Aded /users/@me/connections/:connection_name/:connection_id/access-token
- Replaced `access_token` property on ConnectedAccount with `token_data` object for refreshing tokens
- Made a common interface for connection things like ComonOAuthTokenResponse
- Added `RefreshableConnection` class
- Added token refresh to Spotify connection (disabled)

Don't try to upload entire config for each connection loaded

Switch from Github real name to username for GH connection

Add discriminator usernames for Discord connection

Delete connections

fix discord connection

Add spotify connection

Add reddit connection

Add facebook connection

add epic games connection

WIP Discord connection

Fix ConnectionLoader from throwing when uploading default config keys

Follow Discord docs for `visibility` and `metadata_visibility` fields in ConnectedAccount

entities/ConnectionUpdateSchema -> schemas/ConnectionUpdateSchema

Don't use mergeDeep

`handleCallback` returns connection if created for `USER_CONNECTIONS_UPDATE`

implement PATCH connection

adding connection now works

add connections

Merge pull request #997 from Puyodead1/dev/default-group-dm-avatars ...

Add default group dm icons

Merge pull request #996 from Puyodead1/patch/rename-default-avatars ...

Rename default avatar files

Fix UserSettings relation being in `select` rather than `relations`

add default group dm avatars

use real md5 hash

Remove test client and client patcher

Rename password_reset config to passwordReset as it messes with config key generation

Merge branch 'master' of github.com:fosscord/fosscord-server