KOS urls are partially hardcoded

[DavidLeoni]

Currently disi client as entity/concept/etype identifiers provides urls which point to sweb api, thus if you visit them with the browser you see an ugly json. But in ODR UI, when clicking on meanings user arrives to the nice KOS browser. This happens because in ODR we extrapolate from sweb api urls the entity / concept id and then we append it to the url a KOS service. But we can't hard code things in ODR in this way, so, ideally, the urls we receive from disi client should be global urls pointing to a KOS service that can recognize which MIME type is being requested, if HTML it will display a nice KOS ui, otherwise it will return json.