Unification between engine syncer, order manager and websocket sub conf

[thrasher-]

New Issue

As sub conf is rolled out across most exchanges now, the next steps are unfication with other subsystems. Currently engine's syncer will assume it can fetch ticker/orderbook data from websocket if it's enabled, when I could've disabled ticker/orderbook fetching in the exchanges sub conf. Same goes for per asset sub confgs. If I set websocket to enabled, ticker websocket streaming only for spot instead of all, then the syncer should use REST for the other assets and vice versa. In these cases the syncer will timeout due to no data and failover to REST