Summary

This removes all self-made interfaces such as Message, MessageResponse, and MessagePayload in favour of using eludris-api-types.ts.

Checklist:

This PR has been tested
- The documentation has reflected the changes
- The code has been linted and formatted
This PR fixes an issue
This PR adds a new feature
This PR adds a breaking change
This PR is NOT a code change (e.g. documentation, README, ...)