filesystem: add unit tests for encoder/decoder methods

Lets add test vectors for the per-record/per-file encode/decode of
our various classes for the Elementary Files.

We keep the test vectors as class variables of the respective EF-classes
to ensure implementation and test vectors are next to each other.

The test classes then iterate over all EF subclasses and execute the
decode/encode functions using the test vectors from the class variables.

Change-Id: I02d884547f4982e0b8ed7ef21b8cda75237942e2
Related: OS#4963

pySim/ts_31_102_telecom.py

@@ -124,6 +124,7 @@ class EF_UServiceTable(TransparentEF):
 
 # TS 31.102 Section 4.4.2.1
 class EF_PBR(LinFixedEF):
+    # TODO: a80ac0034f3a02c5034f0904aa0acb034f3d07c2034f4a06
     def __init__(self, fid='4F30', name='EF.PBR', desc='Phone Book Reference', **kwargs):
         super().__init__(fid, name=name, desc=desc, **kwargs)
         #self._tlv = FIXME