Introduce AssetManager

apps/flecs-test/main.cpp

@@ -1,3 +1,4 @@
+#include <asset/asset_manager.h>
 #include <flecs.h>
 #include <input/input.h>
 #include <log/log.h>
@@ -14,6 +15,13 @@ int main()
 
     world.import <Window::WindowModule>();
     world.import <Input::InputModule>();
+    world.import <Asset::AssetModule>();
+
+    Asset::AssetManager manager;
+    manager.register_asset_type<int>(world);
+    auto handle0 = manager.load<int>(world, "hi");
+    auto handle1 = manager.load<int>(world, "hi");
+    auto handle2 = manager.load<int>(world, "hi2");
 
 #ifndef NDEBUG
     world.import <flecs::stats>();