Fix search-page

The search-page, at the moment, is only searching for the title.

We need a clean implementation of a universal search-EP and call it from the frontend, where we can provide every field offered for our search-query.

[Mondei1]

Are you sure this is a bug? I don't think so. I'll changed it.

[Mondei1]

I think what you mean is implement the other option-where-* fields in the header? The universal EP is the "intelligent search". I'll add option-where-number-primary, option-where-number-secondary and option-where-fileextension for now.

Uh... yeah you are right, that was misleading.

This EP is made for letting the user specify in detail, what attributes he wants to add to the search query.

This is NOT meant to be the "universal-search-EP" where the user just inputs some string and the backend tries to make sense of it and applies the splitted substrings into the fitting query-fields :)