Draft: Don't allow duplicate job names

The code here is written to warn the user when there are duplicate job names with RememberJobProgress. It was decided that instead of that approach, we should simply disallow duplicate scheduler job names altogether.

This might cause issues as users would not have a way to edit old .esl files, and it's possible/likely that the mosaic tool generates duplicate job names.

Currently marked draft because of the recoding necessary, and thought required to deal with above.