[FL-1721] Bluetooth refactoring (#747)

* ble-glue: add on connect \ disconnect, on send \ received callbacks
* bt: rework service with furi-hal-bt and callbacks
* bt: update battery level on connect
* ble-glue: set one callback with parameters
* bt: rework callbacks, remove unused API
* ble-glue: remove dead code
* furi-hal-bt: add documentation
* ble-glue: apply changes for f7 target
* bt: rename RpcInstance -> Rpc
* ble: add disconnection reason
* ble: don't open bt record from GAP
* bt: fix RPC session close
* Assets: separate targets for icons and protobuf

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

assets/Makefile

@@ -2,16 +2,20 @@ PROJECT_ROOT		= $(abspath $(dir $(abspath $(firstword $(MAKEFILE_LIST))))..)
 
 include				$(PROJECT_ROOT)/assets/assets.mk
 
-all_assets: $(ASSETS) $(PROTOBUF)
+all: icons protobuf
 
 $(ASSETS): $(ASSETS_SOURCES) $(ASSETS_COMPILLER)
 	@echo "\tASSETS\t\t" $@
 	@$(ASSETS_COMPILLER) icons "$(ASSETS_SOURCE_DIR)" "$(ASSETS_COMPILED_DIR)"
 
+icons: $(ASSETS)
+
 $(PROTOBUF) &: $(PROTOBUF_SOURCES) $(PROTOBUF_COMPILER)
 	@echo "\tPROTOBUF\t" $(PROTOBUF_FILENAMES)
 	@$(PROJECT_ROOT)/lib/nanopb/generator/nanopb_generator.py -q -I$(PROTOBUF_SOURCE_DIR) -D$(PROTOBUF_COMPILED_DIR) $(PROTOBUF_SOURCES)
 
+protobuf: $(PROTOBUF)
+
 clean:
 	@echo "\tCLEAN\t"
-	@$(RM) $(ASSETS)
+	@$(RM) $(ASSETS_COMPILED_DIR)/*