Does it make sense to decode the raw transaction in the wallet-rpc `gettransaction` call (or add an optional parameter to do so)?

See discussion in https://github.com/bitcoin/bitcoin/pull/15159#issuecomment-499051813
HelpExampleCli("listaddressgroupings", "")
            + HelpExampleRpc("listaddressgroupings", "")
                },
            }.Check(request);
    
    
    pwallet->BlockUntilSyncedToCurrentChain();
    auto locked_chain = pwallet->chain().lock();
    LOCK(pwallet->cs_wallet);
    UniValue jsonGroupings(UniValue::VARR);
    std::map<CTxDestination, CAmount> balances = pwallet->GetAddressBalances(*locked_chain);
    for (const std::set<CTxDestination>& grouping : pwallet->GetAddressGroupings()) {
        UniValue jsonGrouping(UniValue::VARR);
        for (const CTxDestination& address : grouping)
        {
            UniValue addressInfo(UniValue::VARR);
            addressInfo.push_back(EncodeDestination(address));
            addressInfo.push_back(ValueFromAmount(balances[address]));
            {
                if (pwallet->mapAddressBook.find(address) != pwallet->mapAddressBook.end()) {
                    addressInfo.push_back(pwallet->mapAddressBook.find(address)->second.name);
                }
            }
            jsonGrouping.push_back(addressInfo);
        }
        jsonGroupings.push_back(jsonGrouping);
    }
    return jsonGroupings;
}
static UniValue signmessage(const JSONRPCRequest& request)