feat(TextureSize): Add parameter to define the textureSize

[AnthonyGlt]

Related issue:

#2292
#2312
#2309

Replace the const use for subdivision and texture conversion with a customizable parameter sizeTextureTile

Example:
For MVT layer

 const mvtSource = new itowns.VectorTilesSource({
              style: 'https://data.geopf.fr/annexes/ressources/vectorTiles/styles/PLAN.IGN/standard.json',
              crs: 'EPSG:3857',

          });

  const mvtLayer = new itowns.ColorLayer('mvtLayer',{
      source: mvtSource,
      sizeTextureTile:512,
      addLabelLayer: true,

  });

For the globe:

const view = new itowns.GlobeView(viewerDiv, placement, {sizeTextureTile:512});

[jailln]

This seems more "source-dependent" than "layer-dependent" because it is related to the source data. I would rather define this in Source. WDYT @Desplandis ?

Then, we should default it to 512 for VectorTileSource.

Also, either here or in Source, can you document it in the public API please?

[Desplandis]

@jailln This seem to be what openlayers does (see https://openlayers.org/en/latest/apidoc/module-ol_source_VectorTile-VectorTile.html).

However, we rasterize the vector data in itowns in the layer (i.e. convert), so it could be a parameter of the layer.

[AnthonyGlt]

We'll keep it in the layer because we have access to the globe layer from there and then we can affect the tile size for the subdivision.
(TODO put a comment in the code)

[mgermerie]

This PR is good to merge in my opinion except for one thing : the name of the parameter.
It think sizeTextureTile (which would sound more correct as tileTextureSize) refers only to the size of a texture. This is not what it describes in one of its two usecases : the tile size above which a globe tile is subdivided.
Perhaps we could benefit from this PR to change the name inherited from the old constant SIZE_TEXTURE_TILE to something like subdivisionThreshold or any other suggestion ?

[AnthonyGlt]

I agree, the name should be changed. subdivisionThreshold is more appropriate but there is sseSubdivisionThreshold already existing.