Evaluating support of address labels for lbcwallet

[roylee17]

Currently, lbcwallet doesn't support address labels. This causes some issues for users to migrate their lbrycrd wallet to lbcwallet.

In some RPCs, lbcwallet overrides the meaning of "label" with "account", for example:

getnewaddress ("account" "addresstype")

Generates and returns a new payment address.

Arguments:
1. account     (string, optional) DEPRECATED -- Account name the new address will belong to (default="default")
2. addresstype (string, optional) Address type. Must be one of legacy / p2pkh, p2sh-p2wpkh / p2sh-p2wkh / p2sh-segwit, or p2wpkh / p2wkh / bech32

Result:
"value" (string) The payment address

importprivkey "privkey" ("label" rescan=true)

Imports a WIF-encoded private key to the 'imported' account.

Arguments:
1. privkey (string, required)                The WIF-encoded private key
2. label   (string, optional)                Unused (must be unset or 'imported')
3. rescan  (boolean, optional, default=true) Rescan the blockchain (since the genesis block) for outputs controlled by the imported key

The desired solution would be supporting labels, and update the RPC semantics to

getnewaddress ("account", "label", "addresstype") // support both account label
importprivkey "privkey" ("label" rescan=true) // respect label

The rest of relevant RPCs are also desired, but not blocking any integration so far.

getaddressesbylabel
getreceivedbylabel
listlabels
setlabel