This commit accomplishes several goals:
1) it removes any upy dependencies from storage.c/storage.h
2) ui wait callback is set during config_init and storage_init,
which allows to simplify the code dramatically
When PIN is entered or changed and their were failed tries the function
waits for time (exponential slow down). For every second it waits, it
now calls back into python to give it the chance to show a message.
GUI still needs to be implemented
