Refs #8531. Added user check if the user has selected nothing

The user is now asked if they're sure they want to process all rows if no rows are selected.
Refs #8531. Corrected script to process all rows

In my edits i had removed a line of code that would include all the rows int eh table, then neglected to put it back after adding the messagebox.

It has since been put back in the code, under the else clause of the Yes/No question response
Merge remote-tracking branch 'origin/feature/8531_Refl_gui_selective_processing'