[FL-2430] Automatic Desktop Locking (#1101)

* Add Auto Lock Time setting
* Update .gitignore
* Add value_index toolbox module
* Auto locking basic implementation
* Better AutoLock implementation, edge cases and cleanup
* Fix NULL pointer crash
* Turn off backlight shortly in locked mode
* Re-enable auto lock after pin lock
* Correctly handle start when pin locked
* Use timer to hide locked hint
* Use a single state variable instead of multiple bools
* Do not call update callback recursively
* Allow input when the Unlocked hint is shown
* Add a delay to backlight switch off while locking
* Better user input handling
* Switch backlight off after pin timeout
* Correct grammar in notification settings

Co-authored-by: あく <alleteam@gmail.com>

applications/desktop/desktop_settings/desktop_settings_app.h

@@ -5,6 +5,7 @@
 #include <gui/view_dispatcher.h>
 #include <gui/scene_manager.h>
 #include <gui/modules/submenu.h>
+#include <gui/modules/variable_item_list.h>
 
 #include "desktop_settings.h"
 #include "desktop/views/desktop_view_pin_input.h"
@@ -13,6 +14,7 @@
 
 typedef enum {
     DesktopSettingsAppViewMenu,
+    DesktopSettingsAppViewVarItemList,
     DesktopSettingsAppViewIdPopup,
     DesktopSettingsAppViewIdPinInput,
     DesktopSettingsAppViewIdPinSetupHowto,
@@ -25,6 +27,7 @@ typedef struct {
     Gui* gui;
     SceneManager* scene_manager;
     ViewDispatcher* view_dispatcher;
+    VariableItemList* variable_item_list;
     Submenu* submenu;
     Popup* popup;
     DesktopViewPinInput* pin_input_view;