refinement: Remove unused osee_join_search_tags table

Change-Id: I7e74fc7dcb6e2240da33de72196dd452508dbfb4
refactor: Remove uses of ConnectionHandler from server-side

Change-Id: Ia943bb5d59194259c42cacdd69f4cc01896402a2
refactor: Remove uses of ConnectionHandler from db.schema

Change-Id: I88b6212d8d4bea07ed37ff3cf37df5404871edf3