Aztec Nargo Doesn't have Serialisation & Deserialization for Signed Integers

[Cheetah0x]

https://github.com/AztecProtocol/aztec-packages/blob/master/noir-projects/noir-protocol-circuits/crates/types/src/type_serialization.nr

In this file there is not serialization and deserialization for signed integers, just for unsigned integers, bools and Fields.