Fix testcase stub of `createModelDataFor`

[machty]

createModelDataFor was the old name before it was changed to createRecordDataFor

[igorT]

@machty can you please add an assert in the code we are stubbing to ensure this time it is getting called.

[machty]

@igorT while addressing your feedback I noticed these tests had an identical setup and what appeared to be a lot of leftover cruft from the original RFC implementation. It's much smaller now, performs the same tests, and the stub assertion you asked for is accomplished just by testing that that the constructed RecordData for a model has the expected type (which is what one of the tests was doing before).

[igorT]

@machty great work!

[runspired]

@machty if you hapeen to have time to rebase this I think the tests will pass and I'd be happy to merge

[runspired]

something is odd here, the more recent commits clearly show test refactoring that the github diff cannot seem to see :/