feat(message): include member data in InteractionReference.user

[shiftinv]

Summary

Previously, message.interaction.user was just a User; the d["interaction"]["member"] data present in MESSAGE_CREATE/_EDIT is now used to turn this into a User | Member instead.

Fairly old apidocs change, seems like it was missed back then: discord/discord-api-docs@56cea94

Checklist

• If code changes were made, then they have been tested
  • I have updated the documentation to reflect the changes
  • I have formatted the code properly by running pdm lint
  • I have type-checked the code by running pdm pyright
• This PR fixes an issue
• This PR adds something new (e.g. new method or parameters)
• This PR is a breaking change (e.g. methods or parameters removed/renamed)
• This PR is not a code change (e.g. documentation, README, ...)

[Skelmis]

Lgtm

[shiftinv]

It's worth mentioning that message["interaction"] has been deprecated in favor of message["interaction_metadata"].
Since interaction_metadata unfortunately doesn't include member data, and because the interaction code handles missing values no matter what, it's fine to implement this regardless for now.