Refactor how the external relations are fetched. refs #18153
Fix in solr client. refs #18153
More refactoring of relations fetching. refs #18153
More refactoring of relations fetching. refs #18153
Do not fetch schemes one by one when prepearing the edit form. refs #18153
Check for unique notation only in the scope of the tenant. refs #18153
Check for empty relations which somehow exist if editing concept with no relations. refs #18153
Merge pull request #26 from picturae/18153

Refactor and optimize the way the external and internal relations are fetched. refs #18153