fix bincode serialization

[Wollac]

Motivation

Fixes bincode deserialization of FixedBytes and Bytes.

Solution

Distinguish between is_human_readable and not also in the deserialization. If it is not human readable (e.g. bincode) allow only bytes instead of also strings.
This fixes #221 .

Added tests for the bincode roundtrip that previously failed.

PR Checklist

• Added Tests
• Added Documentation
• Breaking changes

[DaniPopes]

LGTM after nit and rebase to fix clippy

[DaniPopes]

Nit: I don't think this does anything (same in ../bits)

Suggested change

use bincode as _;

[Wollac]

Without those I got

warning: external crate `bincode` unused in `alloy_primitives`: remove the dependency or add `use bincode as _;`

when building the tests without the serde feature.
I don't know how to avoid this warning. Is there a better way?

[DaniPopes]

Ah I see, it's fine then. I think the problem is that it gets included in the test binaries but not in the library, so it flags it as unused in the library.

[Wollac]

So we decided to have the use in? In both places?
What I don't really understand is why the same is not needed for serde_json. Seems like it's only used in the serde tests as well...

[DaniPopes]

It is:

core/crates/primitives/src/lib.rs

Lines 20 to 24 in 4f7a72c

	// Used in Serde tests.
	#[cfg(test)]
	use serde as _;
	#[cfg(test)]
	use serde_json as _;

[DaniPopes]

Thanks!