Function public_key_of 

pub fn public_key_of<K>(ss58_address: &str) -> Result<Vec<u8>>
where
    K: Key,

Get the public key of the SS58 address.

Substrate reference(s):

• https://github.com/paritytech/substrate/blob/c4d36065764ee23aeb3ccd181c4b6ecea8d2447a/primitives/core/src/crypto.rs#L260-L302