abi.encodePacked for Uint

[ratankaliani]

The implementation of abi.encodePacked for Uint's that are not U256 (ex. U64, U32) is incorrect.

Specifically into_token within encode_packed does not encode the parameters correctly.

Ex.
For abi.encodePacked(uint64, uint32), this is the expected output:

uint64 authoritySetId = 4;
uint32 trustedBlock = 10;
bytes memory encodedBytes = abi.encodePacked(authoritySetId,trustedBlock);
console.logBytes(encodedBytes);

Output:
0x00000000000000040000000a

However, when invoking the same with ethers-rs, this is the output:

let authority_set_id: u64 = 4;
let trusted_block_number: u32 = 10;

let input = encode_packed(&[
    authority_set_id.into_token(),
    trusted_block_number.into_token(),
]).expect("Failed to encode packed data.");
println!("input {:?}", hex::encode(input));

Output:
0x040a

The reason this is the case is that ethabi is the library that ethers-rs uses for encodePacked, and its implementation is deprecated.

Can we move ethers-rs ABI encoding to alloy-rs, which does abi.encodePacked here?

Beyond abi.encodePacked, alloy-rs should be substituted for ethabi as the latter is not actively maintained.

@rellfy Raised a similar issue here: #2494