fix: Fixed strange problem with form_input_clear

* The X had some sort of a strange issue with height, this commit should
  fix it.
update: Added slight polish to bang buttons.

* Previously the bang button would add the bang directly after the query
  text, i.e. 'test!n'. The current implementation changes the behaviour
  and adds a space between the query and the bang (so it would become
  'test !n').