[core] Enable 'line-sort-key' and 'fill-sort-key' layout properties (#15839)

- Generate style code for 'line-sort-key' and 'symbol-sort-key'

- Add new layout properties to FillLayer::Impl, FillBucket, and FillLayerFactory

- Fix consistency of paint and layout properties type alias usage in FillBucket, LineBucket

- Add optional feature sorting to fill and line Layout creation

- Enable node render tests for fill-sort-key and line-sort-key

- Fix FillBucket test construction

- Prefer emplace_back to push_back for PatternFeature container

- Fix buggy static_cast for PatternFeature indices

- Maintain sort of features as they are created

- Switch pattern layout features container to list from vector for better insert performance

- Fix formatting expected by sanity check

- Use subclass PatternLayoutSorted to work around lack of template functions

- Fix to retain source order for features with equivalent sort keys during sorting

- [core] Fix clang-format

- [core] Address review comments

- [core] Pass inserting strategy class at compile time

- [core] Use sorted strategy only if sort key is defined in layout

- [core] Update style generator

- [core] Merge PatternLayout and PatternLayoutSorted classes

  - Use static methods for inserter strategies
  - Merge PatternLayout and PatternLayoutSorted classes

1 files changed, 7 insertions, 1 deletions

diff --git a/src/mbgl/style/layers/line_layer_properties.hpp b/src/mbgl/style/layers/line_layer_properties.hpp
index 29ba9ec641..b2bd4aa401 100644
--- a/src/mbgl/style/layers/line_layer_properties.hpp
+++ b/src/mbgl/style/layers/line_layer_properties.hpp
@@ -36,6 +36,11 @@ struct LineRoundLimit : LayoutProperty<float> {
     static float defaultValue() { return 1; }
 };
 
+struct LineSortKey : DataDrivenLayoutProperty<float> {
+    static constexpr const char *name() { return "line-sort-key"; }
+    static float defaultValue() { return 0; }
+};
+
 struct LineBlur : DataDrivenPaintProperty<float, attributes::blur, uniforms::blur> {
     static float defaultValue() { return 0; }
 };
@@ -88,7 +93,8 @@ class LineLayoutProperties : public Properties<
     LineCap,
     LineJoin,
     LineMiterLimit,
-    LineRoundLimit
+    LineRoundLimit,
+    LineSortKey
 > {};
 
 class LinePaintProperties : public Properties<