[FL-2556] Update complete screen (#1332)

* Desktop: slideshow implementation
* Updater: handling splashscreen installation; added format version field to slideshow binary
* Desktop: added bidirectional slideshow navigation + instant cancel by "back" button; Updater: rebalanced update stages weights
* Updater: fixed missing field init; fixed potential loop when baking slideshows
* Assets: fixed "update complete" image to match original
* Desktop: added check for slideshow file version
* Scripts: slideshow.py cleanup
* Desktop: removed first start intro sequence
* Desktop: removed first start remnants

applications/desktop/views/desktop_events.h

@@ -26,9 +26,6 @@ typedef enum {
     DesktopDebugEventSaveState,
     DesktopDebugEventExit,
 
-    DesktopFirstStartCompleted,
-    DesktopFirstStartPoweroff,
-
     DesktopLockMenuEventLock,
     DesktopLockMenuEventPinLock,
     DesktopLockMenuEventExit,
@@ -37,6 +34,8 @@ typedef enum {
     DesktopAnimationEventNewIdleAnimation,
     DesktopAnimationEventInteractAnimation,
 
+    DesktopSlideshowCompleted,
+
     // Global events
     DesktopGlobalBeforeAppStarted,
     DesktopGlobalAfterAppFinished,