use unionlabs::hash::H256 in evm-storage-verifier

[benluelo]

remove primitive-types usage in this crate and use the types from unionlabs instead: https://github.com/unionlabs/union/blob/main/lib/evm-storage-verifier/Cargo.toml#L12

this should be a pretty trivial swap, since unionlabs::hash::Hash implements rlp encoding:

union/lib/unionlabs/src/hash.rs

Lines 567 to 586 in e652dd1

	impl<E: Encoding, const BYTES: usize> rlp::Decodable for Hash<BYTES, E> {
	fn decode(rlp: &rlp::Rlp) -> Result<Self, rlp::DecoderError> {
	rlp.decoder()
	.decode_value(|bytes| match bytes.len().cmp(&BYTES) {
	core::cmp::Ordering::Less => Err(::rlp::DecoderError::RlpIsTooShort),
	core::cmp::Ordering::Greater => Err(::rlp::DecoderError::RlpIsTooBig),
	core::cmp::Ordering::Equal => {
	Ok(Self::new(bytes.try_into().expect("size is checked; qed;")))
	}
	})
	}
	}
	// TODO: Feature gate rlp across the crate
	// #[cfg(feature = "rlp")]
	impl<E: Encoding, const BYTES: usize> rlp::Encodable for Hash<BYTES, E> {
	fn rlp_append(&self, s: &mut ::rlp::RlpStream) {
	s.encoder().encode_value(self.as_ref());
	}
	}