TST: Add Tests for insert and delete

Integration tests for https://gitlab.indiscale.com/caosdb/customers/lfpb/management/-/issues/394 and caosdb-cpplib!4 (merged).

test/test_transaction.cpp

@@ -116,6 +116,10 @@ TEST(test_transaction, insert_delete) {
   const auto &new_entity = insert_result_set.GetEntity();
   EXPECT_FALSE(new_entity.GetId().empty());
   EXPECT_FALSE(new_entity.HasErrors());
+  // Should have a warning since it has no properties
+  EXPECT_TRUE(new_entity.HasWarnings());
+  EXPECT_EQ(new_entity.GetWarnings().Size(), 1);
+  EXPECT_EQ(new_entity.GetWarnings().At(0).GetCode(), MessageCode::ENTITY_HAS_NO_PROPERTIES);
 
   auto delete_transaction(connection->CreateTransaction());