change nánext document and previous document to use Cmd-Shift-] and [

This will make these command more MacOS like, many other app use this key-binding
need to call onClosed of base class to clean up
trigger event on inline widget close
Merge pull request #6111 from voanhduy1512/change_next_document_command

Add alternate next/previous document shortcuts on Mac: Cmd-Shift-] and [
switch back to capture handler and validate click
verify click is in our dropdown instance
Merge pull request #6176 from adobe/randy/issue-6174

Need to call onClosed of base class to clean up