update string filter UI

+ removes "Search %{field}" translations since you now get to choose the search method
+ updates string filter UI so the method select is side-by-side with the input field
+ moves related JS out of the HTML
Merge pull request #2228 from Daxter/ui/string_filter_side-by-side

update string filter UI
apply translations from #2190; thanks @martinezpenya!
fooo