Add support for OpenStreetMap

[Turcid-uwu]

While the currently supported Map providers are good, I feel OpenStreetMap would be a good choice for those that would not like to create an account on an external service.

I also feel that it's permissive license makes it better choice for an open source application.

[dpaulat]

I would like to add support for this. OpenStreetMap isn't a drop-in replacement for Mapbox or MapTiler though, as they do not host a tile server themselves, so it would require some additional effort.

See the following for some discussion on what something like this might look like:
#481

[JesseWx2011]

I like the concept, though..
Mapbox does implement their data from OpenStreetMap, and OpenStreetMap may be tricky to work with because it doesn't have a full-on documentation compared to Mapbox or Maptiler

[Turcid-uwu]

I'd be interested to help in any I can. Could I get a little more info on what may be needed?

[dpaulat]

I'd be interested to help in any I can. Could I get a little more info on what may be needed?

@Turcid-uwu

This is probably a pretty significant effort, but the discussion in #481 is going to be a valuable starting point if you're up for the challenge.

A couple of thoughts:

• MapLibre already supports MBTiles / PMTiles. Usage of the library needs to be updated to support a local file source, instead of Mapbox or MapLibre.
• The user should be able to select from a few pre-selected sources, as well as a user input source of tiles.
  • The data should only be downloaded if the user requests it
  • The data should probably be cached in the local application settings directory (probably a subdirectory, maybe a tree for each map?), similar to where the existing MapLibre cache is located.
  • Should a subset of the planet be downloaded, or the whole thing? Could be a significant size impact.
• How should layers be handled (or maybe they shouldn't be)?

The Design discussion area (https://github.com/dpaulat/supercell-wx/discussions/categories/design?discussions_q=is%3Aopen+category%3ADesign) is probably the best place to start hashing out some additional details.