Use OpenGL 3.3 core profile instead of compatibility profile

- Rename OpenGL to GLES3 in the source code per community feedback.
  - The renderer is still exposed as "OpenGL 3" to the user.
- Hide renderer selection dropdown until OpenGL support is more mature.
  - The renderer can still be changed in the Project Settings or using
    the `--rendering-driver opengl` command line argument.
- Remove commented out exporter code.
- Remove some OpenGL/DisplayServer-related debugging prints.

platform/osx/detect.py

@@ -189,4 +189,4 @@ def configure(env):
         if not env["use_volk"]:
             env.Append(LINKFLAGS=["-L$VULKAN_SDK_PATH/MoltenVK/MoltenVK.xcframework/macos-arm64_x86_64/", "-lMoltenVK"])
 
-    # env.Append(CPPDEFINES=['GLES_ENABLED', 'OPENGL_ENABLED'])
+    # env.Append(CPPDEFINES=['GLES_ENABLED', 'GLES3_ENABLED'])