scd:p15: Read PuKDF and minor refactoring.
* scd/app-p15.c (pukdf_object_t): New. (struct app_local_s): Add field public_key_info. (release_pukdflist): New. (select_and_read_record): No diagnostic in case of not_found. (read_first_record): New. Factored out from the read_ef_ fucntions. (read_ef_pukdf): New. Basically a copy of read_ef_prkdf for now. (read_p15_info): Also read the public keys. (cardtype2str): New. (read_ef_tokeninfo): Print a string with the cardtype.