bug: unsaved form, if open, remembers deleted magnetic module ID

[IanLondon]

Overview

An unsaved form will remember the old magnetic module ID if you leave it open while you delete and re-add a magnetic module, causing a whitescreen.

Steps to reproduce / Current behavior

• Make a protocol with a magnetic module
• Make a Magnet step form. Leave it open
• Delete the Magnetic Module and create a new one
• Go back and save the Magnet step form that you left open
• Whitescreen! The form you saved retained the ID of the first magnet module, which now points to nothing

Expected behavior

Unsaved form should automatically close (and lose any changes) if a module is deleted, the same way it does if a module is edited

Bonus bug! 2-in-1!

Similarly, if you delete a module, open a Magnet step, and then add a magnet module, the unsaved form retains the null module ID, and prevents you from saving the open Magnet form. (If you cancel the form and open it again, now you can save it). This one isn't a whitescreen, just a confusing UX because for the user, the module ID is not visible or modifiable in the form.

But instead, the unsaved form should just close and lose any changes if a module is added.

Future work??

Maybe we want to add a warning upon adding/deleting a module, or alternatively we could deal with adding/deleting a module updating the unsaved form on a case-by-case basis for different form types (like we do for the saved step forms).