ENH: Add tests for queries

Integration tests for https://gitlab.indiscale.com/caosdb/customers/lfpb/management/-/issues/399 and caosdb-cpplib!7 (merged)

test/test_transaction.cpp

@@ -529,6 +529,18 @@ TEST(test_transaction, test_query) {
   EXPECT_EQ(query_transaction->GetResultSet().Size(), 1);
   EXPECT_EQ(query_transaction->GetResultSet().At(0).GetId(),
             new_entity.GetId());
+  // No count query, so no count result should be present
+  EXPECT_TRUE((query_transaction->GetCountResult() < 0));
+
+  auto count_query_trans(connection->CreateTransaction());
+  count_query_trans->Query("COUNT ENTITY WITH id = " + new_entity.GetId());
+  count_query_trans->Execute();
+  // No result set in a count query
+  EXPECT_EQ(count_query_trans->GetResultSet().Size(), 0);
+  EXPECT_EQ(count_query_trans->GetCountResult(), 1);
 }
 
+// TODO(fspreck) Add tests for unique queries, count queries, and mixed
+// transactions (FIND + RetrieveById, COUNT + RetrieveById).
+
 } // namespace caosdb::transaction