[feature] Implement organizations

[brianfeister]

We have a few concepts floating around via "The Regular" app, including

• Free groups / curators to follow (this was the Meet Near Me conceptual starting point)
• Paid Groups (e.g. monthly fee, includes benefits at restaurants)
• In-between Groups (e.g. even if I don't pay for membership to a group, I want to follow a group and have it's events featured in my feed because I'm essentially a "non-paying member" who will hopefully / optionally convert to paying)

There are a lot of potential places "organizations" as a concept can go, but here is our starting point

• Know user preference / priority for events via hosts that curate events especially for a target demographic and prioritize those events / promote them to users that have opted in / declared their interest by "following"
• "Reshare" / "Cross post" events where Group A can "reshare" an event from "Group B", highlighting it to their members
• Users should be able to "follow" each other, which will show events shared by peers, but also groups / organizations.
• Eventually, we want to have a privacy-first way of showing when friends have RSVPd for an event. The thinking is that the "follow" mechanism will support this, but you only see others who are attending if you mutually follow one another... this adds a bit of data model complexity, as it means that it should be the implicit org of a user that gets followed by other users (even though hidden / not obvious for singular users)
• We want to eventually unlock multiple admins per organization, so each user's account should get an organization provisioned by default, with the option to enhance functionality through paid features like
  • Marketing outreach (SMS / Email to followers) (paid)
  • Custom branding for the org (paid)
  • Custom subdomain (free)