Hide internal util modules?

[meooow25]

We currently expose three such modules:

containers/containers/containers.cabal

Lines 75 to 77 in bb1ec48

	Utils.Containers.Internal.BitUtil
	Utils.Containers.Internal.BitQueue
	Utils.Containers.Internal.StrictPair

I don't think we have enough reason to expose these. They are not containers internals and are not required to use containers internals. They are used purely internally. Two of these, BitUtil and StrictPair, contain only trivial definitions.

Should we move them to other-modules?

[meooow25]

Digging through the history,

• 9fc8b45 exposed all internals "per Ed Kmett's request"
• 576fe49 hid internal utils except for BitUtil and BitQueue. treeowl wrote that these might be useful for users (Refactor internal modules #324 (comment)). According to Hackage search (https://hackage-search.serokell.io/), nobody is using StrictPair or BitQueue. There are two uses of BitUtil: arithmoi uses highestBitMask and enummapset uses bitcount, both of these are gone on HEAD.
• 2eb64f5 exposed StrictPair, reason unclear.

So, we wouldn't be breaking anyone on Hackage, and I am in favor of hiding these to reduce clutter for regular users.