"Leave the replacement text blank to remove an option altogether." does not work when "rewrite text based on key" option is enabled

Problem/Motivation

As stated in the title, removing options only works when not rewriting based on key. This is because of the code in src/BetterExposedFiltersHelper.php where this logic is only performed when specifically not rewriting based on key. However I do not see any clear reason for this being the way it is.

Proposed resolution

Also remove options with empty rewrite values when rewriting based on key instead of generating options with empty labels.