[core] Add expression filter support (#11251)

* WIP

* WIP

* WIP

* Remove Filter::operator()(const Feature&)

* WIP

* WIP

* WIP

* WIP

* Hook up expression filter evaluator

* Replace `shared_ptr` with &reference

* Fill in implementation of `void operator()(const ExpressionFilter&)`

* Fix failing tests

* Switch back to a shared_ptr per chat with @anandthakker

* Fix benchmark compilation

* Shot in the dark to fix CI

* Shot in the dark to fix CI (part 2)

* Shot in the dark to fix CI (part 3)

* In src/mbgl/style/conversion/filter.cpp, add a port of isExpressionFilter and use it to decide in Converter<Filter>::operator() whether to parse the incoming JSON as an ExpressionFilter or one of the legacy filter types

* Remove bool Filter::operator()(const GeometryTileFeature&) const

*  Ensure the map zoom is passed into filtering operations wherever applicable

* Add expression filter tests

* Addressed PR feedback

* Implement `NSPredicate *operator()(mbgl::style::ExpressionFilter filter)`

* Fix formatting& nit

1 files changed, 13 insertions, 0 deletions

diff --git a/src/mbgl/style/filter.cpp b/src/mbgl/style/filter.cpp
new file mode 100644
index 0000000000..51aa6bcf82
--- /dev/null
+++ b/src/mbgl/style/filter.cpp
@@ -0,0 +1,13 @@
+#include <mbgl/style/filter.hpp>
+#include <mbgl/style/filter_evaluator.hpp>
+#include <mbgl/tile/geometry_tile_data.hpp>
+
+namespace mbgl {
+namespace style {
+
+bool Filter::operator()(const expression::EvaluationContext &context) const {
+    return FilterBase::visit(*this, FilterEvaluator { context });
+}
+
+} // namespace style
+} // namespace mbgl