Unique ids broke relation lists preview

[Quicksaver]

- Do you want to request a feature or report a bug?
bug

- What is the current behavior?
PR #1087 broke relation lists preview. Fix coming!

- If the current behavior is a bug, please provide the steps to reproduce.
This is hard, I stumbled upon it while testing locally. Haven't found any example in the demo that shows this. The ListControl component was using the forID property to check for metadata that has a structure like

{ "collection_name": { ... } }

but the changes to ensure forID uniqueness breaks this of course as the metadata doesn't have that unique string in the object's property names.

PR with fix coming!