Currently we have a trait `Hash` that is required for `Hmac`, `Hkdf`,
and other use cases. However, it is unegonomic for users who just want
to do a simple hash to have to import the trait.
Add inherent functions to all hash types including those created with
the new wrapper type macros.
This patch introduces some duplicate code but we are trying to make
progress in the hashes API re-write. We can come back and de-dublicate
later.
Includes making `to_byte_array`,`from_byte_array`, `as_byte_array`, and
`all_zeros` const where easily possible.
We are currently using the `base58::Error` type to create errors in
`bitcoin`, these are bitcoin errors not `base58` errors.
Note that we add what looks like duplicate
`InvalidBase58PayloadLengthError` types but they are different because
of the expected length. This could have been a field but I elected not
to do so for two reasons:
1. We will need to do so anyways if we crate smash more
2. The `crypto::key` one can have one of two values 33 or 34.
With this applied we can remove the now unused error variants from
`base58::Error`.
In preparation for improving the `base58` error types crate an `error`
module and move the single current error type there. Make the module
public and reexport the type.
Add a new `base58` crate to the workspace and move the `bitcoin::base58`
module to it.
Done as part of crate smashing, specifically so that we can make `bip32`
into a separate crate.