NfcDict Refactoring (#3271)

* toolbox(keys_dict): generalize nfc_dict
* nfc: rework nfc app and tests
* toolbox(keys_dict): improve code readability

lib/toolbox/SConscript

@@ -34,6 +34,7 @@ env.Append(
         File("hex.h"),
         File("simple_array.h"),
         File("bit_buffer.h"),
+        File("keys_dict.h"),
     ],
 )