preserve query params in KWS,wildcard suggestions,hints; minor bugfix in url_utils

* fix bug: accessing undefined variable in urlutils
* add a helper function to build links which would preserve the current url parameters (e.g. view, instance, input, limit)
* preserve the selected parameters in:
  - wildcard suggestion links
  - keyword search query result links
  - hint links
* cleanup how hints plugin is added
  - now there's no need to pass the user input arguments, they are taken from request
Merge pull request #4169 from dmwm/preserve_url_params

preserve query params in KWS,wildcard suggestions,hints; minor bugfix in urlutils