Add ignore_columns option to dataframe_comparer.py

[kasztp]

Add ignore_columns option to:
assert_df_equality()
assert_approx_df_equality()

Implementation for #140

PR Checklist

• A description of the changes is added to the description of this PR.
• If there is a related issue, make sure it is linked to this PR.
• If you've fixed a bug or added code that should be tested, add tests!
• If you've added or modified a feature, documentation in docs is updated

Description of changes

Often when comparing dataframes we have some columns which can / should be ignored during the equality check. E.g. timestamp columns, or UUID.

With the implementation of ignore_columns option in:
assert_df_equality(),
and
assert_approx_df_equality(),
functions, users can now specify columns to be ignoered during databrame comparison.

[SemyonSinchenko]

LGTM! Thanks for the contribution!

[SemyonSinchenko]

@kasztp Can you also run a pre-commit with ruff to fix failing code-style check?
https://github.com/MrPowers/chispa/actions/runs/11291104694/job/31447515682?pr=141

[kasztp]

@SemyonSinchenko Done, thanks for spotting!

[kasztp]

@SemyonSinchenko Anything else that needs to be done form my side to get this merged? :)

[SemyonSinchenko]

Sorry, I lost it

[kasztp]

Thanks for the review!