Test for when the models are named and unnamed

Would be important to test for when the models are named and unnamed. That will be easier following up on the alternative flow I suggested [here](https://github.com/epiverse-trace/quickfit/pull/6/files#r1179591282)

_Originally posted by @jamesmbaazam in https://github.com/epiverse-trace/quickfit/pull/6#discussion_r1175260234_

Start by reading the linked pull request #6 discussion, especially the referenced alternative flow, to understand how model names are handled. Add coverage for both named and unnamed models, and consider the work done when the tests distinguish those two cases.

Written by the indexing model from the issue text.