Add command and query for organizations

* Added command and query for organizations
* Saving unknown organizations into database in `background` service
* Added `List` method in `OrganizationRepository`

internal/kurious/adapters/ydb_course_repository.go

@@ -109,6 +109,10 @@ func (conn *YDBConnection) Close() error {
 	return conn.Driver.Close(ctx)
 }
 
+func (conn *YDBConnection) Organization() domain.OrganizationRepository {
+	return domain.NotImplementedOrganizationRepository{}
+}
+
 func (conn *YDBConnection) LearningCategory() domain.LearningCategoryRepository {
 	return domain.NotImplementedLearningCategory{}
 }