fix(Dropdown): make titleText required

[emyarod]

Closes #16602
related #12809

This PR makes the titleText prop required for the dropdown component again to resolve console errors when the prop is undefined

Changelog

Changed

• titleText required in dropdown component agani

Testing / Reviewing

confirm no prop type errors are logged when titleText is missing or undefined in dropdown components

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[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 80.35%. Comparing base (114c71e) to head (871dc65).
Report is 2 commits behind head on main.

Additional details and impacted files

@@           Coverage Diff           @@
##             main   #17886   +/-   ##
=======================================
  Coverage   80.35%   80.35%           
=======================================
  Files         406      406           
  Lines       14041    14041           
  Branches     4395     4395           
=======================================
  Hits        11282    11282           
+ Misses       2593     2592    -1     
- Partials      166      167    +1     

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