NFC Unit tests part 1.1 (#1927)

* Mifare Classic 1/4K, 4/7b uid, NFC-A: NFC-A is not complete yet, as there are no 4b uid tests. Also, Mifare Classic tests don't cover the key cache yet.
* NFC unit tests require access to the NFC app
* Made nfc_device_save accept full path as an argument
* Move from cstrs to furi strings and fix logic
* nfc tests: fix memory leak
* nfc: add mf_classic_get_total_blocks() to API
* nfc tests: simplify nfc tests
* nfc: fix memory leak in shadow file saving
* nfc: fix set uid scene
* nfc: fix saving files
* nfc: fix preload nfc file path
* nfc: remove comments

Co-authored-by: Sergey Gavrilov <who.just.the.doctor@gmail.com>
Co-authored-by: gornekich <n.gorbadey@gmail.com>
Co-authored-by: あく <alleteam@gmail.com>

applications/main/nfc/nfc_i.h

@@ -114,4 +114,6 @@ void nfc_blink_detect_start(Nfc* nfc);
 
 void nfc_blink_stop(Nfc* nfc);
 
+bool nfc_save_file(Nfc* nfc);
+
 void nfc_show_loading_popup(void* context, bool show);