'Ignore' / 'Ignore hidden' in Constraints

[RussellBishop]

Use case:
I have a group full of groups + layers - they all base their Y position as 100% of the previous sibling.

I now want to demo a version where some of those groups + layers are hidden. I don't want to delete them, and I don't want to change the layer order as it's so brittle.

Possible approaches:
Allow constraints to ignore groups / layers when they're hidden.
Allow a setting per-group or per-layer that can toggle it to 'Ignore' when layout is updated.
Allow a setting to add a keyword to group/layer names to have them ignored.