feat(data/sum/order): `with_bot α ≃o punit ⊕ₗ α` and `with_top α ≃o α ⊕ₗ punit` (#15370)
feat(data/sum/order): `with_bot α ≃o punit ⊕ₗ α` and `with_top α ≃o α ⊕ₗ punit` (#15370)



Co-authored-by: Yaël Dillies <aef64c2b10aaee4bd1b6422c57104205a3c50e06@gmail.com>

leanprover-community/mathlib,leanprover-community/mathlib