Refactor `Data.Integer.Divisibility.Signed`

[jamesmckinna]

This is a sequel to #2294 mopping up the refactoring of Data.Integer.Divisibility.Signed suggested there.

NB.

• Data.Integer.Divisibility is still a 'minimal' collection of properties based on the underlying Data.Nat.Divisibility, so this latter module has still to be imported in Data.Integer.Divisibility.Signed, rather than providing a 'clean' API via Data.Integer.Divisibility...
• Additions to Data.Integer.Properties also expose at least one deprecation/refactoring opportunity, between abs-* and ∣i*j∣≡∣i∣*∣j∣, preferring the former over the latter, but not as yet doing the deprecation, in the interests of minimal impact (separate PR?)...
• Possibility to refactor ◃-distrib-*?
• Removes one use of renaming on import, but style-guide recommendation in separate PR #2308 .