fix failing vision tests due to new RAI validation logic which doesn't allow non string dropped column names

[imatiach-msft]

Description

After responsibleai v0.30.0 package release, one of the vision tests started failing due to new validation logic introduced in the v0.30.0 package:

        for column_name in column_names:
            if not isinstance(column_name, str):
>               raise UserConfigValidationException(
                    'Entries in {} must be strings.'.format(column_purpose))
E               raiutils.exceptions.UserConfigValidationException: Entries in dropped feature must be strings.

The new validation logic does not allow dropped features to be non-strings (in this case integers). However, pandas does allow integer column names and in this case the dataset in the test had integer column names. To fix the test, I modified the pandas dataframe integer columns to be text type instead of int type, so that the new validation logic would pass. An alternative fix might be to allow dropped features to have integer values instead of strings.

In addition I changed iloc to use two dimensional indexing always since I noticed the behavior could be different than expected when using metadata features with iloc indexing followed by row index if index is not reset as a safeguard - which I noticed while debugging.

Checklist

• I have added screenshots above for all UI changes.
• I have added e2e tests for all UI changes.
• Documentation was updated if it was needed.

[codecov-commenter]

Codecov Report

Merging #2302 (4bdd8a3) into main (e266587) will decrease coverage by 9.74%.
Report is 2 commits behind head on main.
The diff coverage is 66.66%.

@@            Coverage Diff             @@
##             main    #2302      +/-   ##
==========================================
- Coverage   88.86%   79.12%   -9.74%     
==========================================
  Files         133       26     -107     
  Lines        7550     2199    -5351     
==========================================
- Hits         6709     1740    -4969     
+ Misses        841      459     -382     

Flag	Coverage Δ
unittests	79.12% <66.66%> (-9.74%)	⬇️

Flags with carried forward coverage won't be shown. Click here to find out more.

Files Changed	Coverage Δ
...n/responsibleai_vision/utils/feature_extractors.py	93.10% <50.00%> (ø)
...ext/responsibleai_text/utils/feature_extractors.py	94.55% <100.00%> (ø)

... and 108 files with indirect coverage changes

[github-actions]

https://responsibleai.blob.core.windows.net/pullrequest/microsoft/responsible-ai-toolbox/ilmat/fix-vision-tests/dashboard/index.html