fetch_int -> from_integer; integer_representation -> to_integer

[mkannwischer]

sage deprecated fetch_int and integer_representation in vesion 3.9: https://www.sagemath.org/changelogs/sage-9.8.txt.

I'm getting the following warning when running our code

/usr/lib/python3.12/site-packages/sage/structure/sequence.py:233: DeprecationWarning: fetch_int is deprecated. Please use from_integer instead.
See https://github.com/sagemath/sage/issues/33941 for details.
  x = list(x)  # make a copy even if x is a list, we're going to change it
/tmp/MAYO-sage/sagelib/utilities.py:29: DeprecationWarning: integer_representation is deprecated. Please use to_integer instead.
See https://github.com/sagemath/sage/issues/33941 for details.
  bs += [v[i*_sage_const_2 ].integer_representation() |
/tmp/MAYO-sage/sagelib/utilities.py:30: DeprecationWarning: integer_representation is deprecated. Please use to_integer instead.
See https://github.com/sagemath/sage/issues/33941 for details.

We should switch to from_integer to_integer.
Thanks yx7

[mkannwischer]

Uff - this breaks on still fairly recent sage versions (9.5 in CI) - let's not change this yet.

[claucece]

Let's wait on this one, yes. Let me see if I find the plans to upgrade the CI version..