Prepare for decoding/encoding records differently based on record number

In their infinite wisdom, the authors of the EIRENE FFFIS for GSM-R SIM
cards invented yet a new way of encoding data in SIM card files: The
first record of a file may be encoded differently than further records
of files.

Let's add the required infrastructure to pySim so that the encode and
decode methods for record-oriented files get passed in the current
record number.

Change-Id: I02d6942016dd0631b21d1fd301711c13cb27962b
Related: OS#5784

pySim/ts_31_103.py

@@ -142,11 +142,11 @@ class EF_PCSCF(LinFixedEF):
     def __init__(self, fid='6f09', sfid=None, name='EF.P-CSCF', desc='P-CSCF Address', **kwargs):
         super().__init__(fid=fid, sfid=sfid, name=name, desc=desc, **kwargs)
 
-    def _decode_record_hex(self, raw_hex):
+    def _decode_record_hex(self, raw_hex, **kwargs):
         addr, addr_type = dec_addr_tlv(raw_hex)
         return {"addr": addr, "addr_type": addr_type}
 
-    def _encode_record_hex(self, json_in):
+    def _encode_record_hex(self, json_in, **kwargs):
         addr = json_in['addr']
         addr_type = json_in['addr_type']
         return enc_addr_tlv(addr, addr_type)