M*LIB: non-inlined strings, FuriString primitive (#1795)

* Quicksave 1
* Header stage complete
* Source stage complete
* Lint & merge fixes
* Includes
* Documentation step 1
* FBT: output free size considering BT STACK
* Documentation step 2
* py lint
* Fix music player plugin
* unit test stage 1: string allocator, mem, getters, setters, appends, compare, search.
* unit test: string equality
* unit test: string replace
* unit test: string start_with, end_with
* unit test: string trim
* unit test: utf-8
* Rename
* Revert fw_size changes
* Simplify CLI backspace handling
* Simplify CLI character insert
* Merge fixes
* Furi: correct filenaming and spelling
* Bt: remove furi string include

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

lib/subghz/protocols/base.h

@@ -11,8 +11,9 @@ typedef struct SubGhzProtocolDecoderBase SubGhzProtocolDecoderBase;
 typedef void (
     *SubGhzProtocolDecoderBaseRxCallback)(SubGhzProtocolDecoderBase* instance, void* context);
 
-typedef void (
-    *SubGhzProtocolDecoderBaseSerialize)(SubGhzProtocolDecoderBase* decoder_base, string_t output);
+typedef void (*SubGhzProtocolDecoderBaseSerialize)(
+    SubGhzProtocolDecoderBase* decoder_base,
+    FuriString* output);
 
 struct SubGhzProtocolDecoderBase {
     // Decoder general section
@@ -41,7 +42,7 @@ void subghz_protocol_decoder_base_set_decoder_callback(
  */
 bool subghz_protocol_decoder_base_get_string(
     SubGhzProtocolDecoderBase* decoder_base,
-    string_t output);
+    FuriString* output);
 
 /**
  * Serialize data SubGhzProtocolDecoderBase.