fix: stopped onChange throwing undefined

[Gururajj77]

Closes #18286
Closes #18361

This PR resolves two things:

• stops onChange from getting called again when an already selected item is selected again.
• stops onChange from throwing undefined.

Changelog

Changed

• added the line !isEqual(selectedItemProp, newSelectedItem) to the keyboard event handler inside the onStateChange to make sure we don't call the onChange even when we select the same item.

Testing / Reviewing

• Go to the "On Change Test" story.
• open the console.
• select an item
• there should be log with the selected item
• try to select the same item
• we should not see the same item getting logged again.
• try this using both keyboard and mouse

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[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 84.16%. Comparing base (5a0348c) to head (5970c16).
Report is 1 commits behind head on main.

Additional details and impacted files

@@           Coverage Diff           @@
##             main   #18452   +/-   ##
=======================================
  Coverage   84.16%   84.16%           
=======================================
  Files         408      408           
  Lines       14449    14450    +1     
  Branches     4696     4647   -49     
=======================================
+ Hits        12161    12162    +1     
  Misses       2124     2124           
  Partials      164      164           

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[emyarod]

looks good to me!