Automate donor "hall of fame" generation/updating

[lucko]

There is a new metadata endpoint at: https://metadata.luckperms.net/data/donors

It exports an up-to-date list of donors from the Patreon API, and combines this with a manual list of donations (from GitHub Sponsors or elsewhere) - and makes it available as a metadata endpoint that other services can consume.

The system respects the users privacy settings in Patreon, and only displays public pledges.

The idea is, we can use this endpoint to automatically update the Hall of Fame message in Discord.

My existing message will need to be deleted (clippy can't edit it), but after that, it should be possible to update it!

The metadata endpoint returns the following per user:

{"name":"Luck", "discord":"615647165548724372", "tiers":["Donor"]}

If the user is online/connected to Discord, we can use the Discord API to resolve their user id to their Discord username, and use that in the list.

If not, we can use their full name as given by Patreon.

[lucko]

9fd915b