Add a gltf level exporter (#1719)

* Add a gltf level exporter

* more fixes

* disable by default

* compile fixes for windows

* improve collide packer

* bug fix

* clang format

* fix texture bug

common/custom_data/TFrag3Data.cpp

@@ -277,7 +277,6 @@ void MercModel::serialize(Serializer& ser) {
   for (auto& effect : effects) {
     effect.serialize(ser);
   }
-  ser.from_ptr(&scale_xyz);
   ser.from_ptr(&max_draws);
   ser.from_ptr(&max_bones);
 }

common/custom_data/Tfrag3Data.h

@@ -53,7 +53,7 @@ enum MemoryUsageCategory {
   NUM_CATEGORIES
 };
 
-constexpr int TFRAG3_VERSION = 20;
+constexpr int TFRAG3_VERSION = 21;
 
 // These vertices should be uploaded to the GPU at load time and don't change
 struct PreloadedVertex {
@@ -376,7 +376,6 @@ struct MercEffect {
 struct MercModel {
   std::string name;
   std::vector<MercEffect> effects;
-  float scale_xyz;
   u32 max_draws;
   u32 max_bones;
   void serialize(Serializer& ser);