accounts: Move to instance methods, fix races and isolate tests (#1923)

* Bybit: Fix race in TestUpdateAccountInfo and  TestWSHandleData

* DriveBy rename TestWSHandleData
* This doesn't address running with -race=2+ due to the singleton

* Accounts: Add account.GetService()

* exchange: Assertify TestSetupDefaults

* Exchanges: Add account.Service override for testing

* Exchanges: Remove duplicate IsWebsocketEnabled test from TestSetupDefaults

* Dispatch: Replace nil checks with NilGuard

* Engine: Remove deprecated printAccountHoldingsChangeSummary

* Dispatcher: Add EnsureRunning method

* Accounts: Move singleton accounts service to exchange Accounts

* Move singleton accounts service to exchange Accounts

This maintains the concept of a global store, whilst allowing exchanges
to override it when needed, particularly for testing.

APIServer:

* Remove getAllActiveAccounts from apiserver

Deprecated apiserver only thing using this, so remove it instead of
updating it

* Update comment for UpdateAccountBalances everywhere

* Docs: Add punctuation to function comments

* Bybit: Coverage for wsProcessWalletPushData Save

exchanges/binance/binance.go

@@ -820,17 +820,14 @@ func getOfflineTradeFee(price, amount float64) float64 {
 
 // getMultiplier retrieves account based taker/maker fees
 func (e *Exchange) getMultiplier(ctx context.Context, isMaker bool) (float64, error) {
-	var multiplier float64
-	account, err := e.GetAccount(ctx)
+	a, err := e.GetAccount(ctx)
 	if err != nil {
 		return 0, err
 	}
 	if isMaker {
-		multiplier = float64(account.MakerCommission)
-	} else {
-		multiplier = float64(account.TakerCommission)
+		return float64(a.MakerCommission), nil
 	}
-	return multiplier, nil
+	return float64(a.TakerCommission), nil
 }
 
 // calculateTradingFee returns the fee for trading any currency on Binance