Delivery: Use current roots during delivery

[iLLiCiTiT]

Changelog Description

Make sure that root is not re-used from published representation during delivery.

Additional info

Because we do copy "context" it also copied "root" there, if root is filled in template data, anatomy does not auto-fill it which causes issues during delivery.

Testing notes:

1. Publish some representation (can skip if you have any).
2. Create new root in the project.
3. Use the new root in delivery template.
4. Run delivery action in loader.
5. It should work fine and should not raise error because of missing root key.

[BigRoy]

Question @iLLiCiTiT - before this PR ... there may be usage of delivery templates of {root} in delivery templates. That would break now because one would require now to specify the children? Or was root already a dict in context too?

[iLLiCiTiT]

there may be usage of delivery templates of {root} in delivery templates.

I don't think it was, you would still have to use {root[...]} in template.

Or was root already a dict in context too?

Yes, but only with one root, and one platform.