`residue_for_atom` should give a `view` instead instead of a `copy`

[egolep]

I'm playing with both the bindings for Julia and Python, and while working with residues on a liposome, I found that, in the Julia version, Residue and residue_for_atom are making copies of the residue instead of giving a view, like in the Python version where a raed-only access is given. The problem is that the Julia version is unusable for me because of the memory consumption that comes with doing so much copies of potentially big data structures.
Is there a workaround that I haven't been able to find? Otherwise, I think that we should be using views or giving the possibility to choose if the function does a copy or not