How to display concept search

[nichtich]

Ui and functionality of concept search needs to be clarified and implemented before release of 1.0.0.

[stefandesu]

This is both about the search field (currently, there's no separate search field for concept search) as well as the results display.

For the backend, I would keep using the configured JSKOS API provider's results directly, though this will get more complicated if multiple providers can be configured.