Preallocate more vectors in the CUTEstModel

Suggested by Dominique in #375.
We should discuss what we want to support in `CUTEst.jl`.
If the user provides vector stored in a precision different of the `CUTEstModel`, should we handle it?

Start by reading the suggestion in issue #375 and the surrounding CUTEst.jl interface context. Clarify which additional vectors should be preallocated and whether vectors with precision different from the CUTEstModel must be supported. Done means the project has an agreed scope and corresponding implementation plan.

Written by the indexing model from the issue text.