[FL-3841] FuriEventLoop Pt.2 (#3703)

* Abstract primitive type from main logic in FuriEventLoop
* Remove message_queue_i.h
* Add stream buffer support for event loop
* Add semaphore support for event loop
* Add temporary unit test workaround
* Make the linter happy
* Add mutex support for event loop
* Implement event subscription and unsubscription while the event loop is running
* Implement edge events
* Fix leftover logical errors
* Add event loop timer example application
* Implement flag-based edge trigger and one-shot mode
* Add event loop mutex example application
* Only notify the event loop if stream buffer is at or above its trigger level
* Reformat comments
* Add event loop stream buffer example application
* Add event loop multiple elements example application
* Improve event loop flag names
* Remove redundant signal handler as it is already handled by the event loop
* Refactor Power service, improve ViewHolder
* Use ViewHolder instead of ViewDispatcher in About app
* Enable ViewDispatcher queue on construction, deprecate view_dispatcher_enable_queue()
* Remove all invocations of view_dispatcher_enable_queue()
* Remove app-scened-template
* Remove missing library from target.json
* Port Accessor app to ViewHolder
* Make the linter happy
* Add example_view_holder application, update ViewHolder docs
* Add example_view_dispatcher application, update ViewDispatcher docs
* Replace FuriSemaphore with FuriApiLock, remove workaround delay
* Fix logical error
* Fix another logical error
* Use the sources directive to speed up compilation
* Use constant define macro
* Improve FuriEventLoop documentation
* Improve FuriEventLoop documentation once more
* Bump API Version
* Gui: remove redundant checks from ViewDispatcher
* Gui: remove dead ifs from ViewDispatcher

Co-authored-by: Silent <CookiePLMonster@users.noreply.github.com>
Co-authored-by: hedger <hedger@users.noreply.github.com>
Co-authored-by: あく <alleteam@gmail.com>

applications/settings/about/about.c

@@ -1,9 +1,12 @@
 #include <furi.h>
-#include <dialogs/dialogs.h>
+
 #include <gui/gui.h>
-#include <gui/view_dispatcher.h>
+#include <gui/view_holder.h>
 #include <gui/modules/empty_screen.h>
+
+#include <dialogs/dialogs.h>
 #include <assets_icons.h>
+
 #include <furi_hal_version.h>
 #include <furi_hal_region.h>
 #include <furi_hal_bt.h>
@@ -204,7 +207,8 @@ const AboutDialogScreen about_screens[] = {
     about_screen_cert_taiwan,
     about_screen_cert_mexico,
     about_screen_hw_version,
-    about_screen_fw_version};
+    about_screen_fw_version,
+};
 
 int32_t about_settings_app(void* p) {
     UNUSED(p);
@@ -212,18 +216,15 @@ int32_t about_settings_app(void* p) {
     DialogMessage* message = dialog_message_alloc();
 
     Gui* gui = furi_record_open(RECORD_GUI);
-    ViewDispatcher* view_dispatcher = view_dispatcher_alloc();
+    ViewHolder* view_holder = view_holder_alloc();
     EmptyScreen* empty_screen = empty_screen_alloc();
-    const uint32_t empty_screen_index = 0;
 
     size_t screen_index = 0;
     DialogMessageButton screen_result;
 
     // draw empty screen to prevent menu flickering
-    view_dispatcher_add_view(
-        view_dispatcher, empty_screen_index, empty_screen_get_view(empty_screen));
-    view_dispatcher_attach_to_gui(view_dispatcher, gui, ViewDispatcherTypeFullscreen);
-    view_dispatcher_switch_to_view(view_dispatcher, empty_screen_index);
+    view_holder_attach_to_gui(view_holder, gui);
+    view_holder_set_view(view_holder, empty_screen_get_view(empty_screen));
 
     while(1) {
         if(screen_index >= COUNT_OF(about_screens) - 1) {
@@ -258,8 +259,8 @@ int32_t about_settings_app(void* p) {
     dialog_message_free(message);
     furi_record_close(RECORD_DIALOGS);
 
-    view_dispatcher_remove_view(view_dispatcher, empty_screen_index);
-    view_dispatcher_free(view_dispatcher);
+    view_holder_set_view(view_holder, NULL);
+    view_holder_free(view_holder);
     empty_screen_free(empty_screen);
     furi_record_close(RECORD_GUI);