Rename `consBag`/`snocBag` to `extendBag` and use `OrdList` where order matters
Motivation
In short: Bag is documented to be an "unordered collection", so it doesn't make sense that there is both consBag and snocBag.
Proposal
- Rename
consBag/snocBagtoextendBag - Use
OrdListinstead in code that actually relies on the order in which elements are inserted into theBag