make push-named functions consistently (push object collection)

[stylewarning]

cel:push! doesn't match vec:push!. CL has (push object collection).

Edit: Possibly use other names for other argument orders?

[gefjon]

(push collection object) is, IMO, a more useful order for currying. (vec:push! my-vec) should be :elt -> Unit push into my-vec, so you can use it on things like iter:for-each!.

[stylewarning]

OTOH for an immutable collection:

COALTON-USER> (coalton
               (pipe
                (seq:new)
                (seq:push 5)
                (seq:push 6)
                (map 1+)))
#<Seq[2] 6 7>

[Izaakwltn]

I'd like to start this discussion back up ->

I think my alignment is with:
(push collection object)
(get collection index)
(put collection index object)

If we could get the decision finalized I'm happy to go through and fix instances throughout.

I started a poll at: #996 with three order options