engine: Adds shutdown method to exchange manager and unload all exchanges when engine is stopped (#1112)

* engine: shutdown and unload exchange when engine is stopped

* linter: fixes

* engine/exchMan: add nil check

* engine/exchanges: add shutdown method to exchanges, rm len check lock not needed, expanded code coverage, address some nits

* exchMan: report all failed shutdowns across exchanges, implement timer and monitoring routines.

* exchMan: improve shutdown sequence and aloc.

* further improvement

* exchman: log from warn to error

* websockconnection: Suppress error return when closure is caused by library

* linter: fix

* fix racies

* add note on why not parallel tests

* glorious: nits

* spelling kween

* thrasher: nits

* engine: change print of setting using reflection, I keep forgetting to implement this so program around forgetfulness

* engine/exchange_management: remove wait group and just rely on intermediary lock

* glorious: nits

* Update common/common.go

Co-authored-by: Adrian Gallagher <adrian.gallagher@thrasher.io>

* Update main.go

Co-authored-by: Adrian Gallagher <adrian.gallagher@thrasher.io>

---------

Co-authored-by: Ryan O'Hara-Reid <ryan.oharareid@thrasher.io>
Co-authored-by: Adrian Gallagher <adrian.gallagher@thrasher.io>

exchanges/binanceus/binanceus_websocket.go

@@ -100,9 +100,10 @@ func (bi *Binanceus) KeepAuthKeyAlive() {
 	// ClosUserDataStream closes the User data stream and remove the listen key when closing the websocket.
 	defer func() {
 		er := bi.CloseUserDataStream(context.Background())
-		log.Errorf(log.WebsocketMgr,
-			"%s closing user data stream error %v",
-			bi.Name, er)
+		if er != nil {
+			log.Errorf(log.WebsocketMgr, "%s closing user data stream error %v",
+				bi.Name, er)
+		}
 	}()
 	// Looping in 30 Minutes and updating the listenKey
 	ticks := time.NewTicker(time.Minute * 30)