API Endpoint to list who reacted to a status

[easrng]

Pitch

I'm implementing showing who reacted to a status in my client, and that information doesn't seem to be exposed here. Akkoma has /api/v1/pleroma/statuses/:id/reactions, fedibird has status.emoji_reactions[].account_ids, but it doesn't look like Chuckya has any equivalent.

Motivation

Right now Chuckya users don't seem to be able to see who reacted to a post. This is inconsistent with both favorites and how other fedi servers handle reactions.

[TheEssem]

There is an experimental API in #11; it still needs to be cleaned up a bit however, and I'm still waiting for review to make sure it's suitable for usage in clients.