[New Handler] Discord channels

[tahpot]

We already have a basic Discord provider.

Add support for pulling discord channels and messages.

Add support for pulling direct messages (I'm not sure if the API supports this?)

[tahpot]

Change of scope, for the first release, we only process direct messages.

Processing of all workspaces and channels will come in the future, when there is a UI for a user to select which ones to sync.

[chime3]

Issues

• Discord has also placed restrictions on DM-related APIs to protect user privacy. It requires Discord approval.
  

• We should verify discord app before moving forward. It throws following error.
  

[tahpot]

This is pending @tahpot verifying the Discord app and requesting DM access from Discord

[tahpot]

@chime3 Discord app is now verified, please confirm you can access the necessary endpionts.

[chime3]

@chime3 Discord app is now verified, please confirm you can access the necessary endpionts.

There is no explicit mention of the deprecation of the dm_channels.read scope, but whenever I try to add DM scopes, it still says the OAuth2 scopes are malformed. We might need to catch up with the Discord team.