[feature] Streaming swaps #check-lint-warning

Fixes #1514 (closed)

To utilize a streaming swap, instead of putting a number in the "trade target", use the following

<trade target>/<swap frequency>/<swap quantity>

On each swap attempt the network will track how much (in funds) failed to swap and how much was successful. After all swap attempts are made (specificed by "swap quantity"), the network will send out all successfully swapped value, and the remaining source asset (that failed to swap for some reason, most likely due to the trade target).

If the first swap attempt fails for some reason, the entire streaming swap is refunded and no further attempts will be made.

If the <swap quantity> is set to zero, the network will determine the number of swaps on its own with a focus on lowest fees, max quantity of trades.