[FL-1955] CLI RPC (#781)

- RPC: added CLI command to start session - all input bytes goes into RPC, all RPC output goes into VCP
- RPC: added command to close session (actually it only notifies transport layer)
- RPC: added recursive rmdir
- RPC: hard-coded listing for root directory (any, ext, int)
- Fixed CLI leak
- Fixed furi_record_delete leak
- Unit tests: repaired
- Unit tests: corrected output - remove excess, change dots with progress spinner
- Unit tests: added leak check
- Unit tests: SD mount check before start

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

applications/tests/furi_record_test.c

@@ -11,7 +11,10 @@ void test_furi_create_open() {
     // 2. Open it
     void* record = furi_record_open("test/holding");
     mu_assert_pointers_eq(record, &test_data);
+
+    // 3. Close it
     furi_record_close("test/holding");
 
+    // 4. Clean up
     furi_record_destroy("test/holding");
 }