Cannot use unordered_elements_are for long lists of elements.

This is a regression from #754. I use to have a list of 22 elements in my unordered_elements_are. Unfortunately matcher tuple impls only go up to length 11 as far as I can tell, so switching to using tuples internally means my matcher is no longer valid.

This broke in a patch version, so I think this should be rolled back?

Start at the unordered_elements_are matcher and inspect the matcher tuple implementations, which currently appear to support lengths only through 11. Reproduce the regression with a list of 22 elements and compare the behavior introduced by #754. Done means long unordered_elements_are lists work again without breaking existing matcher behavior.

Written by the indexing model from the issue text.