Give the Searchbar a PF4 look

One of the things that kinda prevent us from switching pages to PF4 design is that most of the pages contain bootstrap design.

I believe we should just start with it, and one component by component give our app a more fresh look,
this PR starts with the Searchbar so we could move to other parts of the page and they would all fit,
there is also an RFC for the table and pagination: Apply table PF4 classname and use PF4 pagination