[TASK] Add slack to nonces to allow them to increment at most 1024.

[drewstone]

https://github.com/webb-tools/protocol-substrate/blob/831117d132ed7dd867ae0acd5d27ea7a3f369932/pallets/signature-bridge/src/lib.rs#L222-L229

[drewstone]

We should also fix it once added on the relayer.