Automatically set the property for window classes/application the user manually attached or detached to scratch layer

[oatmealm]

Is your feature request related to a problem? Please describe.

It could be an improvement of the current workflow.
Right now the user needs to manually identify and add the wm_class.

Describe the solution you'd like

If the user has manually attached a window to the scratch layer it should be automatically marked to open there next time launched. If manually detached, should be marked accordingly. This will save the need to add and remove manually.