Better privacy/self reliance for immich tile map

[rouke-broersma]

Immich downloads the map tiles from their server on map-load. This means the map does not work if this is offline. It also means that client-data such as location requests for photos are shared with immich. This is not a huge issue, but it would be nice to offer an easy option to host this ourselves.

A middle ground could be a caching proxy. We are likely to often need map tiles for the same areas, which can easily be cached indefinitely on our own servers:

https://github.com/pcouy/pcouy.github.io/blob/main/_posts/2024-08-30-proxying-a-map-tile-server-for-increased-privacy.md

Or we could host our own mapping service, which would mostly cost disk space (~100Gib for the whole world): https://protomaps.com/