Reimplemented Renderer2D

- Renderer2D now static
- Renderer now calls Init and Deinit of Renderer2D
- Renderer2D  now calls Init and Deinit of FontRenderer
- Fixed Deinit order of Layers and renderer (e.g. Layers now deinit first)
- Sandbox2D now uses SandboxApp (only loads different layer)

GlitchyEngine/src/Renderer/BufferVariable.bf

@@ -113,6 +113,12 @@ namespace GlitchyEngine.Renderer
 			*(T*)firstByte = value;
 		}
 		
+		[Inline]
+		private T GetData<T>()
+		{
+			return *(T*)firstByte;
+		}
+
 		public void SetData(bool value) => SetData<bool>(value);
 
 		public void SetData(float value) => SetData<float>(value);