do not send "wallet" socket when funding an order from an external wallet

[rmisio]

Funding an order from an external wallet results in a "wallet" socket:

The "wallet" socket is intended to monitor transactions of the internal wallet. Funding an order from an external wallet doesn't affect the transactions of the internal wallet. When you get a "wallet" socket in this case, it results in a false positive for clients thinking a user has a new internal wallet transaction, when they do not.

[rmisio]

FWIW, @cpacia and I discussed having separate sockets for transaction updates for an order vs. the wallet. In that scenario, if a transaction was from the wallet for an order, both sockets would fire.

Having the separate sockets would also solve this bug, since there would be no "wallet" socket for orders that are funded from an external wallet.