feat: handle textarea tab / shift tab events

[benjamincanac]

Adds shift and shift+tab events on textarea in live edit mode.

Types of changes

• Bug fix (a non-breaking change which fixes an issue)
• New feature (a non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)

[codecov-commenter]

Codecov Report

❗ No coverage uploaded for pull request base (dev@396378c). Click here to learn what that means.
The diff coverage is n/a.

@@          Coverage Diff           @@
##             dev     #289   +/-   ##
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  Coverage       ?   90.21%           
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  Files          ?       15           
  Lines          ?      552           
  Branches       ?      118           
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  Hits           ?      498           
  Misses         ?       48           
  Partials       ?        6           

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