Model overview: add cohort selection hint

[romanlutz]

Description

So far we didn't give users any kind of hint as to what the cohort selection flyout does or how they are supposed to interact with it:

This PR changes that! Below you see the strings at the top (above the choice group and dropdown). The two pictures show the same strings, but I thought it makes sense to see it in both configurations.

Default without features selected:

With feature selected:

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 #1496 (9cd6053) into main (f9aaf3b) will increase coverage by 2.35%.
The diff coverage is n/a.

@@            Coverage Diff             @@
##             main    #1496      +/-   ##
==========================================
+ Coverage   87.56%   89.91%   +2.35%     
==========================================
  Files         108       89      -19     
  Lines        5081     3839    -1242     
==========================================
- Hits         4449     3452     -997     
+ Misses        632      387     -245     

Flag	Coverage Δ
unittests	89.91% <ø> (+2.35%)	⬆️

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

Impacted Files	Coverage Δ
raiwidgets/raiwidgets/__version__.py
raiwidgets/raiwidgets/constants.py
raiwidgets/raiwidgets/__init__.py
raiwidgets/raiwidgets/fairness_dashboard.py
raiwidgets/raiwidgets/dashboard.py
raiwidgets/raiwidgets/responsibleai_dashboard.py
raiwidgets/raiwidgets/interfaces.py
...iwidgets/raiwidgets/model_performance_dashboard.py
raiwidgets/raiwidgets/model_analysis_dashboard.py
...iwidgets/raiwidgets/explanation_dashboard_input.py
... and 9 more

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[github-actions]

https://responsibleai.blob.core.windows.net/pullrequest/microsoft/responsible-ai-toolbox/romanlutz/model_overview_feature_selection_hint/dashboard/index.html

[github-actions]

https://responsibleai.blob.core.windows.net/pullrequest/microsoft/responsible-ai-toolbox/romanlutz/model_overview_feature_selection_hint/dashboard/index.html

[github-actions]

https://responsibleai.blob.core.windows.net/pullrequest/microsoft/responsible-ai-toolbox/romanlutz/model_overview_feature_selection_hint/dashboard/index.html

[github-actions]

https://responsibleai.blob.core.windows.net/pullrequest/microsoft/responsible-ai-toolbox/romanlutz/model_overview_feature_selection_hint/dashboard/index.html

[github-actions]

https://responsibleai.blob.core.windows.net/pullrequest/microsoft/responsible-ai-toolbox/romanlutz/model_overview_feature_selection_hint/dashboard/index.html

[github-actions]

https://responsibleai.blob.core.windows.net/pullrequest/microsoft/responsible-ai-toolbox/romanlutz/model_overview_feature_selection_hint/dashboard/index.html