The search box previously displayed a clear icon on the far right
side in webkit-based browsers, specifically Chrome and Safari. This
hides the clear icon in those browsers, and also fixes a slight
sizing issue, so it should no longer be displayed.
This also disables autocorrect, autocompleted, as well as a few
other automatic search corrections on the field, so mobile devices
should have a better experience.
This closes https://github.com/select2/select2/issues/3018.