feat: attachments in interaction responses

[Droid00000]

Summary

Adds support for sending files (attachments) in interaction responses and closes out #227.

Added

attachments KWARG to interaction response methods.

Changed

Something akin to this for most interaction response/webhook API calls.

 body = if attachments
          files = [*0...attachments.size].zip(attachments).to_h
          { **files, payload_json: { type: type, data: body }.to_json }
        else
          { type: type, data: body }.to_json
        end