RPC: Implement storage_stat_request (#800)

* RPC: Update protobuf sources
* RPC: Implement storage_stat_request
* RPC: Test storage_stat_request
* FuriRecord: fix use after free in destroy method.
* Furi: refactor PubSub and it's usage. Fix allocation in RPC.
* FuriCore: fix memory leak in pubsub
* FuriCore: update unsubscribe method signature in pubsub, make subscription structure lighter.
* FuriCore: remove dead code

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

applications/gui/icon_animation.c

@@ -2,7 +2,6 @@
 #include "icon_i.h"
 
 #include <furi.h>
-#include <timers.h>
 
 IconAnimation* icon_animation_alloc(const Icon* icon) {
     furi_assert(icon);