Currently we implement `Deref` for hashes. From the docs [0]
> Deref should only be implemented for smart pointers to avoid confusion
Furthermore because we implement `Deref` as well as implement
`internals::hex::display::DisplayHex` for slices hashes get coerced into
slices and `to_lower_hex_string` can be called on them, this is
incorrect because `DisplayHex` does not account for hashes that display
backwards so we end up with the wrong string.
[0] https://doc.rust-lang.org/std/ops/trait.Deref.html