Add CheatEngine and support for Gateway cheats (#4406)

* Add CheatEngine; Add support for Gateway cheats; Add Cheat UI

* fix a potential crash on some systems

* fix substr with negative length

* Add Joker to the NonOp comp handling

* Fixup JokerOp

* minor fixup in patchop; add todo for nested loops

* Add comment for PadState member variable in HID

* fix: stol to stoul in parsing cheat file

* fix misplaced parsing of values; fix patchop code

* add missing break

* Make read_func and write_func a template parameter

src/citra_qt/CMakeLists.txt

@@ -24,6 +24,8 @@ add_executable(citra-qt
     camera/qt_camera_base.h
     camera/qt_multimedia_camera.cpp
     camera/qt_multimedia_camera.h
+    cheats.cpp
+    cheats.h
     citra-qt.rc
     configuration/config.cpp
     configuration/config.h
@@ -134,6 +136,7 @@ set(UIS
     multiplayer/client_room.ui
     multiplayer/host_room.ui
     aboutdialog.ui
+    cheats.ui
     hotkeys.ui
     main.ui
     compatdb.ui