When decoding the SELECT response of a clasic GSM SIM without
UICC functionality, we
* did not decode the record length or number of records
* accidentially reported the EF file_size as available_memory (like DF)
Let's fix those two, and also add a comment on how the output dict
of decode_select_response() should look like.
As a result, code like 'read_records' now knows the number of records
and can iterate over them rather than raising exceptions.
Change-Id: Ia8e890bda74e3b4dacca0673d6e5ed8692dabd87
Closes: OS#5874