Show elapsedTime for query in Plan Text output

The query execution plan provided by the Plan Text button in the query workbench is frequently used for debugging purposes by Support.

Typically, the output after clicking the Plan Text button is copied to a text file by a customer, then uploaded to Support for debugging, meaning we usually receive a text file that solely contains the Plan Text output.

As this doesn't contain the total execution time of the query, we often have to request that that customers specify this manually. This is not reliably provided, meaning we are rarely able to see the total execution time of a query that we are looking at the Plan Text output for. 

Adding the total execution time for the query (elapsedTime) in the Plan Text output itself would help eliminate the need to specify this separately when sharing the Plan Text output. This would also help ensure we reliably have this information without depending on customers to manually share this.