Implement `resampling` paint property to raster, hillshade, color relief layers

[larsmaxfield]

Implement resampling paint property to raster, hillshade, color relief layers

This issue tracks the implementation of resampling as a new style spec paint property for raster, hillshade, and color relief layers.

• Style spec issue: Add resampling paint property to color relief, hillshade layers maplibre-style-spec#1447
• GL JS issue: Implement resampling paint property to raster, hillshade, color relief layers maplibre-gl-js#7154

Examples

layers: [
  {
    id: 'raster',
    type: 'raster',
    source: 'rasterSource',
    paint: {
      'resampling': 'nearest',  // 'linear' or 'nearest'; default 'linear'
      'raster-resampling': 'nearest',  // Soft-deprecated
      ...
    },
  },
  {
    id: 'hills',
    type: 'hillshade',
    source: 'hillshadeSource',
    paint: {
      'resampling': 'nearest',  // 'linear' or 'nearest'; default 'linear'
      ...
    },
  },
  {
    id: 'color-relief',
    type: 'color-relief',
    source: 'colorReliefSource',
    paint: {
      'resampling': 'nearest',  // 'linear' or 'nearest'; default 'linear'
      ...
    },
  },
]

resampling	'nearest'	'linear'
Hillshade
Color relief

Impact

No change to existing functionality. The default resampling for raster, hillshade, and color relief remains bilinear. The new property lets us opt-in to nearest neighbor for color relief and hillshade layers, which was previously limited to only rater layers.