Hide already refined layers

[dlhagger]

Point to this discussion for more details - https://forum.image.sc/t/napari-labeling-gui-issues/77317

The lack of documentation and default to show all layer levels is confusing for the user when refining labels. Is there a way to automatically hide already refined layers when extracting and refining future labels in the GUI upon loading the labels folder for an associated video?

[backyardbiomech]

As an easier to code alternative to hiding layers, it might be good enough (for now) to have the latest machine-labels layer show edges by default when the folder is loaded. The user then can just work with that layer selected, move labels, and ignore other layers when the markers don't have edges shown. Then the "save layers" when called on that latest machine layer appends those data to CollectedData. Documenting the workflow will be helpful too.