Changes

personalization: implement reading back values from a PES

Implement get_values_from_pes(), the reverse direction of apply_val():
read back and return values from a ProfileElementSequence. Implement for
all ConfigurableParameter subclasses.

Future: SdKey.get_values_from_pes() is reading pe.decoded[], which works
fine, but I07dfc378705eba1318e9e8652796cbde106c6a52 will change this
implementation to use the higher level ProfileElementSD members.

Implementation detail:

Implement get_values_from_pes() as classmethod that returns a generator.
Subclasses should yield all occurences of their parameter in a given
PES.

For example, the ICCID can appear in multiple places.
Iccid.get_values_from_pes() yields all of the individual values. A set()
of the results quickly tells whether the PES is consistent.

Rationales for reading back values:

This allows auditing an eSIM profile, particularly for producing an
output.csv from a batch personalization (that generated lots of random
key material which now needs to be fed to an HLR...).

Reading back from a binary result is more reliable than storing the
values that were fed into a personalization.
By auditing final DER results with this code, I discovered:
- "oh, there already was some key material in my UPP template."
- "all IMSIs ended up the same, forgot to set up the parameter."
- the SdKey.apply() implementations currently don't work, see
  I07dfc378705eba1318e9e8652796cbde106c6a52 for a fix.

Change-Id: I234fc4317f0bdc1a486f0cee4fa432c1dce9b463