Backport test utility functions

The resultset processing functions are helpful in writing tests that
process resultsets.

maxscale-system-test/mariadb_func.cpp

@@ -515,6 +515,36 @@ int find_field(MYSQL* conn, const char* sql, const char* field_name, char* value
     return ret;
 }
 
+Result get_result(MYSQL* conn, std::string sql)
+{
+    Result rval;
+    MYSQL_RES* res;
+
+    if (mysql_query(conn, sql.c_str()) == 0 && (res = mysql_store_result(conn)))
+    {
+        MYSQL_ROW row = mysql_fetch_row(res);
+
+        while (row)
+        {
+            rval.emplace_back(&row[0], &row[mysql_num_fields(res)]);
+            row = mysql_fetch_row(res);
+        }
+        mysql_free_result(res);
+    }
+    else
+    {
+        printf("Error: Query failed: %s\n", mysql_error(conn));
+    }
+
+    return rval;
+}
+
+Row get_row(MYSQL* conn, std::string sql)
+{
+    Result res = get_result(conn, sql);
+    return res.empty() ? Row{} : res[0];
+}
+
 int get_int_version(std::string version)
 {
     std::istringstream str(version);