Fix freeze when resizing a window (#239)

Fixed an annoying bug where the application would freeze when resizing
the window
This pull request made it so the SDL window's resizing event now
broadcasts a new event specifically asking the swapchain to recreate
itself, which will in turn broadcast the original event when done. It
also removed the Event enum specific values, as they were irrelevant.

runtime/Includes/Core/Enums.h

@@ -19,9 +19,10 @@ namespace mlx
 
 	enum class Event
 	{
-		ResizeEventCode = 56,
-		FrameBeginEventCode = 57,
-		FatalErrorEventCode = 168,
+		ResizeEventCode = 1,
+		SwapchainResizeEventCode,
+		FrameBeginEventCode,
+		FatalErrorEventCode,
 
 		EndEnum
 	};