started implementation for a trait that fits LightWallet and LightWatch

[fluidvanadium]

this is the start of an fv-style implementation of LightPocket

[zancas]

I think we want:

trait Auditor {}

impl Auditor for TransactionRecordsById {}

trait SpendCapable: Auditor {
        type SpendCapabilities
}

[zancas]

I clicked update branch. Is this design change still something we're considering?

[zancas]

Hi @fluidvanadium is this code still destined for merge?