Revise the DatDatabase worker run_query method to combine the results of multiple runs if an optional argument is passed

When the Database worker run_query method is triggered with a value set as $args[1], instead of sending an email, append the response value to a file. The name of the file will be what is passed as $args[1]. Otherwise, the run_query function should continue to run as it does now.

Create a new function in the Database worker called email_run_query_results that will then read from the file that was created and send a single email based on the same logic of the run_query function.