[Feature] Add FixedBytes and aliases macros

[DaniPopes]

Component

No response

Describe the feature you would like

Exported macro_rules! that wrap hex_literal::hex! with $crate::<type> constructors. Also re-export hex! itself

Additional context

No response

[startup-dreamer]

I would like to work on this @DaniPopes could you please provide additional direction on this.

[prestwich]

we'd like a wrapper around hex! that also instantiates a alloy_primitives::FixedBytes so that users can declare a fixed bytes inline easily

• the macro should live in alloy_primitives and be exported
• the macro should have thorough documentation
• the internals of the macro are something like $crate::FixedBytes( hex! { ... } )
• there should be a similar macro for address! that uses $crate::Address and for any other newtype in the primitives crate

sample code:

let my_bytes: FixedBytes<4> = bytes! { "1234 abcd" };
let output = bytes!{ "12 34" } & bytes!{ "ab cd" };

const DOMAIN_HASH: FixedBytes<32> = bytes! { 
    "a191312024065f51f1eb9e5ffc5795890db9e0a5bc0eacb250d5034d1e990302" 
};

[DaniPopes]

Sorry @startup-dreamer I already had an implementation this morning, you can check out other issues tagged with good first issue if you want to take on another issue.

[startup-dreamer]

No worries, I will work on some other issue.