Python example syntax

[simbilod]

Many examples, run out of the box*, give errors of type:

Traceback (most recent call last):
  File "/home/simbil/Github/ViennaPS/examples/GDSReader/GDSReader.py", line 27, in <module>
    plane = vls.lsDomain(bounds, boundaryConds, gridDelta)
            ^^^^^^^^^^^^
AttributeError: module 'viennals3d' has no attribute 'lsDomain'. Did you mean: 'Domain'?

Implementing the suggested change, as is done everywhere relevant in this PR, makes the scripts run.

*unless I set things up wrong! I followed the README of ViennaLS and ViennaPS

[tobre1]

Thank you for updating the examples!

It seems we overlooked updating some of them with the latest changes to the library.