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_connection.cpp

@@ -73,7 +73,8 @@ TEST(test_connection, connection_insecure_authentication_error_anonymous) {
   EXPECT_THROW(connection.RetrieveVersionInfo(), AuthenticationError);
 }
 
-TEST(test_connection, connection_ssl_authentication_error_anonymous) {
+// TODO(tf) cognitive complexity > 25 (threshold)
+TEST(test_connection, connection_ssl_authentication_error_anonymous) { // NOLINT
   const auto *port_str =
     caosdb::utility::get_env_var("CAOSDB_SERVER_GRPC_PORT_HTTPS", "8443");
   auto port = std::stoi(port_str);
@@ -92,7 +93,9 @@ TEST(test_connection, connection_ssl_authentication_error_anonymous) {
                        "succeed. Original error: Please login.");
 }
 
-TEST(test_connection, connection_ssl_authentication_error_wrong_credentials) {
+// TODO(tf) cognitive complexity > 25 (threshold)
+TEST(test_connection,                                         // NOLINT
+     connection_ssl_authentication_error_wrong_credentials) { // NOLINT
   const auto *port_str =
     caosdb::utility::get_env_var("CAOSDB_SERVER_GRPC_PORT_HTTPS", "8443");
   auto port = std::stoi(port_str);