Support Polls

[mplatypus]

Summary

Support polls from the discord documentation https://discord.com/developers/docs/resources/poll,

Why is this needed?

This is needed because polls are cool 😎 (and also a new API feature)

Ideal implementation

To be decided.

Checklist

• [X] I have searched the issue tracker and have made sure it's not a duplicate. If it is a follow up of another issue, I have specified it.