Tests: Account for extra focus/blur listeners in jQuery >=3.4

Tests: Account for extra focus/blur listeners in jQuery >=3.4

jQuery >=3.4.0 uses a special focus/blur handler pair
needed to fix various issues with checkboxes/radio buttons
as well as being able to pass data in focus triggers.
However, this leaves dummy focus & blur events if any of these
events were ever listened to at a particular element. There's not
a lot UI can do to fix this so we now just skip these handlers for
data comparisons in tests.

Ref jquery/jquery#4496
Closes gh-1930

Co-authored-by: Richard Gibson <richard.gibson@gmail.com>