DEV: Replace jquery.putCursorAtEnd (PR #9390)

Removes old jquery.putCursorAtEnd plugin and replaces it with a utility function. Also removes fallback for browsers that don’t support setSelectionRange.

Note also that triggering the putCursorAtEnd even immediately in composer-title.js is by design, the delay introduced by afterTransition breaks setting focus on iOS devices (we currently don’t set focus on iOS, but this PR is step 1 of getting to a point where we can do that).


Awesome! I’m looking forward to seeing these ios fixes.