Fix sorting with ?version=diffs

Cleans up query parameters when `?version=` is present on GET/item. Bugs identified when researching #331.

Note that while tests are passing, I haven't actually been able to manually verify the results here because of #332.

Also, most of the time the tests are failing on `eve.tests.methods.get.TestGet.test_get_sort_disabled`, but sometimes they aren't. I don't think the results are impacted by these changes. Trash cat is not amused.