feat: dusking dbcs

[grumbach]

• includes sn_dbc code in sn_transfers

gets rid of DBCs and uses the new nomenclature:

• SNT: the unit of our currency
• NanoTokens : (currently Token) 10^-9 SNT
• CashNote: (currently DBC), spendable unique key along with spend related information, containing n nanos. This CashNote contains unique key related information, leaking it damages privacy but it cannot be spent by an attacker since it doesn’t contain your private key.
• Spend/SignedSpend: Network representation of a spent CashNote, it cannot be linked back to your MainKey. It makes the system auditable and transactions verifiable
• Transaction: (currently DbcTransaction), Network operation that creates new CashNote while spending CashNote of the same total value, transaction information is findable both in CashNotes and in the Spends on the Network.
• CashNoteRedemption: (currently UTXO) minimal information from which the recipient of a Transaction can redeem their new spendable CashNote
• Transfer: encrypted NoteRedemptions ready to be sent to a transaction recipient so they can receive money.

As for keys:

• MainSecretKey: (current MainKey) the private main key (secret)
• DerivedSecretKey: (current DerivedKey) a derived key from the main key (IS UNIQUE but secret)
• MainPubkey: (current PublicAddress) the public key of the main key
• UniquePubkey: (current dbc_id) the public key of the derived key (IS UNIQUE)

Description

reviewpad:summary

[happybeing]

Is CashNote straying away from utility token and towards money?

[joshuef]

Is CashNote straying away from utility token and towards money?

This change in nomenclature will be elaborated upon a dev update 👍 .

But to be clear: this PR has no changes to how tokens and transfers operate on the network over the previous dbc crate. It's all being rolled in here and naming updated to better reflect what's actually happening