fix(text-area): style resize knob (VIV-1620)

[rachelbt]

• Firefox is not supported, but it also has a different style where the knob is bigger and not hidden under the box-shadow (the outline).
• The ui tests are not presenting the resize knob in FF & safari at all- @YonatanKra maybe you know why?

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 100.00%. Comparing base (d61b119) to head (7b7ef52).
Report is 855 commits behind head on main.

Additional details and impacted files

@@             Coverage Diff             @@
##              main     #1626     +/-   ##
===========================================
  Coverage   100.00%   100.00%             
===========================================
  Files          123       312    +189     
  Lines         1562      5026   +3464     
  Branches       108       563    +455     
===========================================
+ Hits          1562      5026   +3464     

Flag	Coverage Δ
unittests	100.00% <ø> (ø)

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