Rasters: Add tileSize to TileJSON

[roblabs]

Add tileSize to TileJSON Output for Raster endpoints

1. This PR would add to the Tile JSON implementation:
   i. tileSize
2. The TileJSON 3.0.0 spec is missing a Tile Size concept for rasters.
   i. There is discussion at tilejson-spec#26.
   ii. The Sources spec for Mapbox & MapLibre make use of tileSize.

---

Tests

Using the default Zurich tile set with a basic preview. Paths are mentioned in the docs at Rendered Tiles.

"The optional tile size /{tileSize} (ex. /256, /512). If omitted, tileSize defaults to 256."

• TileJSON output without a tileSize set:
  • http://localhost:8080/styles/basic-preview.json

  "tiles": [ "http://localhost:8080/styles/basic-preview/{z}/{x}/{y}.png" ],
  "tileSize": 256

• TileJSON output with tileSize set to 256:
  • http://localhost:8080/styles/256/basic-preview.json

  "tiles": [ "http://localhost:8080/styles/basic-preview/256/{z}/{x}/{y}.png" ],
  "tileSize": 256

• TileJSON output with tileSize set to 512:
  • http://localhost:8080/styles/512/basic-preview.json

  "tiles": [ "http://localhost:8080/styles/basic-preview/512/{z}/{x}/{y}.png" ],
  "tileSize": 512

Note: the path to the TileJSON does not exactly match the pattern for the path the PNG, but those are the verified paths.

---

Note on TileJSON 2.0.0 v. TileJSON 3.0.0++

• TileJSON 2.0.0#2. File format discusses how to deal with extra keys: "implementations MUST expose unknown key/values in their API so that API users can optionally handle these keys"

[roblabs]

cf. Line 997 where tileSize is set

const tileSize = parseInt(req.params.tileSize, 10) || undefined

[acalcutt]

ya, I made this default to undefined for a reason. When I added 512 tiles and added tileSize, I wanted to preserve the old behavior when the user went to the old /style/id.json endpoint urls (which returned a 256px tile before). When it is undefined, getTileUrls returns a tile url that does not have a tilesize included (like it did before). When tileSize is defined, the size gets included in the tiles url.

[acalcutt]

I am not really concerned with adding tileSize to our tilejson. The spec seems to say as long as the required fields are included that the tilejson is valid. the client is supposed to ignore the unknow key values, but obviously some clients are able to use this already (like maplibre) and just having that information would be helpful (since if it doesn't read it directly they may need to know the size so they can set it themeselfs)

[acalcutt]

can you run npm run lint:js:fix and see if it fixes the CI

[roblabs]

Thanks to @acalcutt for catching & running Lint for me. I had been doing development via Docker