New MetricsOverlay tracking, general bug fixes and changes

[valkyrienyanko]

New Features

• Devs can now track any variable they want in the MetricsOverlay with the new StartTracking method

Bug Fixes

• Moved framework to be outside of res://addons as the game engine was refusing to see scenes inside that folder
• Fixed missing icon path hopefully for good this time
• All broken dependencies have been fixed

Template Changes

• Reorganize ALL project files and group by scene instead of separating by scripts and scenes
• Removed several unused scripts and images
• Locked relevant nodes in their respective scenes
• Moved individual asset credit.txt files to wiki for now
• Menu UI scenes no longer break SceneManager.cs when they are moved
• Options saving and loading no longer relies on Godot and instead uses raw json (hotkeys are still using Godot resource saver)
• Exports null checker has been removed as maybe you want certain exports to stay as null
• Readonly modifier warning suppressed in .editorconfig as [Export]'s should not have this
• All json files saved to user:// are now indented for easier reading
• Fix some naming issues

GodotUtil Changes

• Added CacheManager.cs in GodotUtils
• Added some TaskUtil helper functions in GodotUtils
• Removed Reparent function in GodotUtils as already exists in Godot