fix: remove messages 'Using strings as events are deprecated'

src/libs/grafana/events/events.ts

@@ -0,0 +1,16 @@
+import {AppEvent} from './appEvents';
+
+export interface GraphHoverPayload {
+    pos: any;
+    panel: {
+        id: number;
+    };
+}
+
+export var graphHover:(AppEvent<GraphHoverPayload>|string) = {name: 'graph-hover'};
+export var graphHoverClear:(AppEvent<any>|string) = {name: 'graph-hover-clear'};
+
+export function fallbackToStringEvents() {
+    graphHover = 'graph-hover';
+    graphHoverClear = 'graph-hover-clear';
+}