Add timezone command opt-in ability for guild and users

[fisher60]

Summary

Users/members should have to opt in to have their timezones shared in each server. Currently if a user has added a timezone and they are in a guild where the timezone list command is being called, their timezone will be displayed. Regardless if they added the timezone in that specific server.

Implementation

User should have a many-to-many field to the guilds that they have opted into for the timezone command. The guild they originally set the timezone command in should default to opted in. User also needs ability to opt out and remove that guild from the many to many.

Graphql should list the the guild IDs of each opted in guild. Guild id will be required when setting a timezone as well as when opting in.

[fisher60]

This change should be reflected in the front end in the template view as well, a user should be able to choose which guilds to share data in as a an option in the profile view.