fix(GuildEmojiManager): throw an error if image resolving fails

[SpaceEEC]

Please describe the changes this PR makes and why it should be merged:

This PR fixes #3933.

The method was recursing endlessly if anything falsy (such as omitting the parameter) was passed as attachment.

I moved the DataResolver#resolveImage call to the top of the method and made the method throw an error (REQ_RESOURCE_TYPE) if resolving failed.

Status

• Code changes have been tested against the Discord API, or there are no code changes
• I know how to update typings and have done so, or typings don't need updating

Semantic versioning classification:

• This PR changes the library's interface (methods or parameters added)
  • This PR includes breaking changes (methods removed or renamed, parameters moved or removed)
• This PR only includes non-code changes, like changes to documentation, README, etc.

Stale