feat(operator_doc): include operator usage examples in the operator documentation

[PProfizi]

This PR updates the ansys.dpf.core.documentation package to integrate script usage examples for C++, IPython and CPython in the operator documentation for the DPF Framework documentation.

[PProfizi]

Here is an example of how they render when I build the DPF Framework doc for 26R1 locally:

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 84.41%. Comparing base (b587c58) to head (573ff49).
⚠️ Report is 2 commits behind head on main.
✅ All tests successful. No failed tests found.

Additional details and impacted files

@@           Coverage Diff           @@
##             main    #2777   +/-   ##
=======================================
  Coverage   84.41%   84.41%           
=======================================
  Files          92       92           
  Lines       10944    10964   +20     
=======================================
+ Hits         9238     9255   +17     
- Misses       1706     1709    +3     

[PProfizi]

Here is an example PR on DevRelDocs using these changes (before I removed the empty C# examples)
https://github.com/ansys/DevRelDocs/pull/278/files