Rework start/stop api to use runtime-event notification message

packages/node_modules/@node-red/editor-client/locales/en-US/editor.json

@@ -169,6 +169,10 @@
         }
     },
     "notification": {
+        "state": {
+            "flowsStopped": "Flows stopped",
+            "flowsStarted": "Flows started"
+        },
         "warning": "<strong>Warning</strong>: __message__",
         "warnings": {
             "undeployedChanges": "node has undeployed changes",
@@ -291,12 +295,6 @@
     "stopstart":{
         "status": {
             "state_changed": "Flows runtime has been changed to '__state__' state"
-        },
-        "errors": {
-            "notAllowed": "Method not allowed",
-            "notAuthorized": "Not authorized",
-            "notFound": "Not found",
-            "noResponse": "No response from server"
         }
     },
     "deploy": {