[core] Add MapOptions to define properties of Map

To simplify the Map constructor, introduce MapOptions
interface to define the properties that can be set on
a Map.

test/api/custom_layer.test.cpp

@@ -2,6 +2,7 @@
 
 #include <mbgl/platform/gl_functions.hpp>
 #include <mbgl/map/map.hpp>
+#include <mbgl/map/map_options.hpp>
 #include <mbgl/util/default_thread_pool.hpp>
 #include <mbgl/storage/default_file_source.hpp>
 #include <mbgl/gl/defines.hpp>
@@ -94,7 +95,7 @@ TEST(CustomLayer, Basic) {
     float pixelRatio { 1 };
     HeadlessFrontend frontend { pixelRatio, fileSource, threadPool };
     Map map(frontend, MapObserver::nullObserver(), frontend.getSize(), pixelRatio, fileSource,
-            threadPool, MapMode::Static);
+            threadPool, MapOptions().withMapMode(MapMode::Static));
     map.getStyle().loadJSON(util::read_file("test/fixtures/api/water.json"));
     map.jumpTo(CameraOptions().withCenter(LatLng { 37.8, -122.5 }).withZoom(10.0));
     map.getStyle().addLayer(std::make_unique<CustomLayer>(