Extend `GenericCollectionAssertions` to include a `ContainInConsecutiveOrder`

Description

We were writing tests where we needed to check if one collection contained another in order. For this, we used ContainInOrder.

However, we found that because ContainInOrder doesn’t check that the items are consecutive we could introduce mutations in the code and our tests would still pass.

To solve this we have made a new method in the same class, GenericCollectionAssertions, called ContainInConsecutiveOrder. This is a stricter version of the current check, adding the check that the expected items all appear in consecutive order. For completeness, we also introduced the opposite NotContainInConsecutiveOrder.

The API change is an extension to the API, with, as far as I can see, no breaking changes.

We have implemented these changes, with associated tests, in a branch and would like to submit a PR.

[jnyrup]

I’m good with ContainInConsecutiveOrder.

@lg2de Thanks for your perspectives (here and elsewhere in the repo). I’m happy to have your extra set of eyes to ensure we leave no stone unturned.

[dennisdoomen]

Although I don’t dislike the proposal, my problem is that we already took a certain (ad-hoc) path where we have distinct methods for distinct goals. If we would have taken this design principle as a starting point, we could have done that. And we still can, but it would be a major breaking change that would require a major review of all APIs to see what they would look like in a major new version. Not only would this require a lot of work and planning, it would also be a major breaking change for our installed base without gaining a lot.