Pandas API Addons: add_prefix and add_sufix

[marcosvm13]

Feature

• Please insert link to associated issue here: Initial addition of pytest #4

What does this change introduce?

An implementation of the add_prefix and add_suffix function: https://pandas.pydata.org/docs/reference/api/pandas.DataFrame.add_prefix.html
https://pandas.pydata.org/docs/reference/api/pandas.DataFrame.add_suffix.html#pandas.DataFrame.add_suffix

Note: In Pandas the index attribute does not change the result (only the columns are changed, not the indexes). In this implementation, prefixes or suffixes can be added to indexes in addition to columns.

General

• Has an example been added to demo the new feature?
• Have existing examples been updated or tested?
• Have you added any new Environment Variables/Configuration Options? If yes please tick the boxes below as applicable
  • Addition to reimporter logic within src/pykx/pykx.q and src/pykx/reimporter.py
  • Have updated the src/pykx/util.py logic which is used for environment variable
• If there have been any dependency updates have they been reflected in all files?
  • pyproject.toml
  • docs/getting-started/installing.md
  • conda-recipe/meta.yaml
  • README.md
• If any examples have been updated has it's associated .zip been updated

Code

• Has all temporary code used during development been removed?
• Has all commented out (unused) code been removed?
• Where reasonable have you ensured there is no duplication of existing code?
• If applicable for your use-case have you ensured that the code is performant?

Testing

• Have unit tests been created or existing ones updated to test this new functionality?

Documentation

• Has documentation been added for all public code?
• Has a release note been included for the new feature?
• Has any documentation which would benefit from this feature been updated to use the most up to date functionality?
• If a new class has been added has a documentation stub .md file associated with it been created?
• If any documentation page has been created has it been added to mkdocs.yml
• Have you checked your changes with a spell checker? (US English)