Qt: Allow rebinding keyboard controls (#779)

* Initial input UI draft

Co-Authored-By: Paris Oplopoios <parisoplop@gmail.com>

* More keybinding work

Co-Authored-By: Paris Oplopoios <parisoplop@gmail.com>

* Nit

Co-Authored-By: Paris Oplopoios <parisoplop@gmail.com>

* More nits

Co-Authored-By: Paris Oplopoios <parisoplop@gmail.com>

---------

Co-authored-by: Paris Oplopoios <parisoplop@gmail.com>

src/panda_sdl/mappings.cpp

@@ -1,7 +1,7 @@
-#include "input_mappings.hpp"
-
 #include <SDL.h>
 
+#include "input_mappings.hpp"
+
 InputMappings InputMappings::defaultKeyboardMappings() {
 	InputMappings mappings;
 	mappings.setMapping(SDLK_l, HID::Keys::A);