fix: Move pure methods out of External crate

[evgenykuzyakov]

External crate should only contain methods that requires something external to complete. E.g. when interacting with the blockchain.
Pure functions such as sha256 and keccak hashes can go directly to vm-logic.
Bumping versions to 1.1.0
Fixes: #3019

Test plan:

• CI

[gitpod-io]

[willemneal]

Looks good but am confused with the spacing e.g.

        use sha2::Digest;

        let value_hash = sha2::Sha256::digest(&value);

        self.internal_write_register(register_id, value_hash.as_ref().to_vec())

[evgenykuzyakov]

Looks good but am confused with the spacing e.g.

I separated use since it's import, but the space between the last 2 can be removed.

[willemneal]

Also as a Rust noob, is there a reason to import so late?

[evgenykuzyakov]

Also as a Rust noob, is there a reason to import so late?

I think we import Digest to be local only to avoid name conflict with other Digest(s).