Handle 0x prefix str for Address

[yanganto]

Currently, Address type can use from_str to build the instance, for example.

let charman_address = Address::from_str("8663DBF0cC68AaF37fC8BA262F2df4c666a41993")?;

The API just fit and easily for the developer using web3.js before.

And there is a similar another API in Rust crate web3.

let charman_address = Address::from_str("0x8663DBF0cC68AaF37fC8BA262F2df4c666a41993")?;

So it is good to make this the 0x prefix input also work in sewup, such that developer can use this much easier.

[carlosfrodrigues]

I can take this issue! Can you assign this for me?

[yanganto]

Hey @carlosfrodrigues,
If you run into problems, you are welcome to ask help here.
😄