UI: Add opt. to enable/disable in-focus hotkey blocking

Adds an option to enable/disable blocking hotkeys when the window is in
focus which is normally used in order to prevent hotkey/shortcut
conflicts.  This does not apply to the settings window; the hotkey
behavior is unchanged with the settings window (in order to prevent
hotkeys from being used while setting hotkeys for example).

Closes obsproject/obs-studio#1267

UI/obs-app.hpp

@@ -73,6 +73,9 @@ private:
 	os_inhibit_t                   *sleepInhibitor = nullptr;
 	int                            sleepInhibitRefs = 0;
 
+	bool                           enableHotkeysInFocus = true;
+
+
 	std::deque<obs_frontend_translate_ui_cb> translatorHooks;
 
 	bool InitGlobalConfig();
@@ -80,6 +83,8 @@ private:
 	bool InitLocale();
 	bool InitTheme();
 
+	inline void ResetHotkeyState(bool inFocus);
+
 public:
 	OBSApp(int &argc, char **argv, profiler_name_store_t *store);
 	~OBSApp();
@@ -87,6 +92,8 @@ public:
 	void AppInit();
 	bool OBSInit();
 
+	void EnableInFocusHotkeys(bool enable);
+
 	inline QMainWindow *GetMainWindow() const {return mainWindow.data();}
 
 	inline config_t *GlobalConfig() const {return globalConfig;}