Default routing options for trading strategies.
The strategy Routing model defines how individual trades are split to different blockchain transactions. Furthermore, we might need to do a currency conversion between our strategy reserve currency and the trading pair quote token and this is a part of the routing.
TradeRouting, we define the default routing model options a trading strategy can have.
There is also a custom user_supplied_routing_model option in which case you need to construct
the routing model in the code yourself.
What trade routing should the strategy use.