Added context for the MasterClient's methods to avoid endless loops (#5628)

* Added context for the MasterClient's methods to avoid endless loops

* Returned WithClient function. Added WithClientCustomGetMaster function

* Hid unused ctx arguments

* Using a common context for the KeepConnectedToMaster and WaitUntilConnected functions

* Changed the context termination check in the tryConnectToMaster function

* Added a child context to the tryConnectToMaster function

* Added a common context for KeepConnectedToMaster and WaitUntilConnected functions in benchmark

weed/command/master_follower.go

@@ -140,7 +140,7 @@ func startMasterFollower(masterOptions MasterOptions) {
 	}
 	go grpcS.Serve(grpcL)
 
-	go ms.MasterClient.KeepConnectedToMaster()
+	go ms.MasterClient.KeepConnectedToMaster(context.Background())
 
 	// start http server
 	httpS := &http.Server{Handler: r}