/browse/reports - add institution relationships & country details

[ctueck]

The reports list/search results should include:

• the institutions' hierarchical relationship details and
• the institutions' country details, including the official status in the country.
  This should be under each object in the institutions array, not aggregated, so that we can see which country comes from which institution (and the respective status flag).

The existing country array with just names in it can stay for compatibility.

Also, the report detail endpoint now has the hierarchical and historical relationships only aggregated, not per institutions. Preferably this should also be moved under each object in the institutions array.

Institution country details should also be added in report detail view.

In both list + detail view, the hierarchical relationship details should include the dates (to recognise which ones are current).