addmultisigaddress creates an address respecting the setting, being unable to generate a specific type of address without also adding it to the wallet seems wrong.

I suppose in the future `addresstype` may be refactored to be wallet-specific, which would leave this non-wallet rpc call without an argument. Perhaps there should just be an optional parameter to set it.
{
        UniValue obj(UniValue::VOBJ);
        CScript subscript;
        CRIPEMD160 hasher;
        uint160 hash;
        hasher.Write(id.begin(), 32).Finalize(hash.begin());
        if (pwallet && pwallet->GetCScript(CScriptID(hash), subscript)) {
            ProcessSubScript(subscript, obj);
        }
        return obj;
    }
    UniValue operator()(const WitnessUnknown& id) const { return UniValue(UniValue::VOBJ); }
};
static UniValue DescribeWalletAddress(CWallet* pwallet, const CTxDestination& dest)
{
    UniValue ret(UniValue::VOBJ);
    UniValue detail = DescribeAddress(dest);
    ret.pushKVs(detail);
    ret.pushKVs(boost::apply_visitor(DescribeWalletAddressVisitor(pwallet), dest));
    return ret;
}
static UniValue AddressBookDataToJSON(const CAddressBookData& data, const bool verbose)