refactor: OPTIC-1501: remove a collection of ff

[luarmr]

A group of simple FF that were stale an we dice to remove them in the same pull request to avoid the conflict when merge.

• ff_dev_2128_html_in_labels_150422_short as True
• ff_front_dev_2431_delete_polygon_points_080622_short as True
• ff_front_dev_2575_projects_list_performance_280622_short as True
• fflag_feat_front_dev_2461_audio_paragraphs_seek_chunk_position_short as True but no real code behind, looks like was a bad clean up.
• fflag_fix_front_dev_3730_shortcuts_initial_input_22122022_short as True

All of this are LSO only.

You may want to review commit by commit and with whitespace option enabled.
First commit is empty since I create a ticket to group this work

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[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 76.80%. Comparing base (61e141e) to head (71e8185).
Report is 2 commits behind head on develop.

Additional details and impacted files

@@           Coverage Diff            @@
##           develop    #6879   +/-   ##
========================================
  Coverage    76.80%   76.80%           
========================================
  Files          171      171           
  Lines        14031    14031           
========================================
+ Hits         10776    10777    +1     
+ Misses        3255     3254    -1     

Flag	Coverage Δ
pytests	76.80% <ø> (+<0.01%)	⬆️

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