Bring Remora.Discord back in Parity with Discord

[VelvetToroyashi]

Description

Remora is currently missing a few (somewhat critical) features that Discord has added in the last two to three months.

These include the following, with approximate timescales for implementing said features:

• Forwarding Messages (1-2 days)
• Entrypoint Commands (a few hours)
• Incoming Webhook Events (a few hours)
• Message updates now always give a full message object (>1 hour)
• User-App user install count (>1 hour)
• Voice States can now be fetched over HTTP (~2-3 hours)

Why This is Needed

Discord adds new features, we implement new features

Alternatives Considered

Monkey-patching the library is always an option, albeit cumbersome and far from ideal

Additional Details

No response