Remove hardcoded SDL controller mapping from UWP build

[StephenCWills]

See #6930 (comment)

I remember now that the Xbox One/Xbox Series build had some custom startup code that attempted to swap the A/B and X/Y buttons using SDL controller mappings.

devilutionX/uwp-project/src/SDL_winrt_main_NonXAML.cpp

Lines 65 to 82 in 9a148ab

	std::string controllerMapping = ",*,a:b1,b:b0,x:b3,y:b2,back:b6,start:b7,leftstick:b8,rightstick:b9,leftshoulder:b4,rightshoulder:b5,dpup:b10,dpdown:b12,dpleft:b13,dpright:b11,leftx:a1,lefty:a0~,rightx:a3,righty:a2~,lefttrigger:a4,righttrigger:a5,platform:WinRT";
	for(int i = 0; i < SDL_NumJoysticks(); ++i)
	{
	SDL_JoystickType type = SDL_JoystickGetDeviceType(i);
	if(type == SDL_JOYSTICK_POWER_UNKNOWN)
	continue;
	SDL_JoystickGUID guid = SDL_JoystickGetDeviceGUID(i);
	if(!guid.data)
	continue;
	char guidString[33];
	SDL_JoystickGetGUIDString(guid, guidString, 33);
	SDL_GameControllerAddMapping((guidString + controllerMapping).c_str());
	}

Now that we are able to detect controller type, this code should be unnecessary. But it's worse than that because I've found that it's subject to a race condition. Sometimes this code runs before the SDL event that adds the game controller. Discord user Tree reported it on Discord back in August 2022, and I think there was another report even before that so I think that confirms it happens on Xbox hardware. I have never run the build on anything but Windows, but I was also able to reproduce the issue there.