feat: basic support for annotations (#11)

Author: ye11ow

src/datasource.ts

@@ -3,6 +3,8 @@ import { DataSourceWithBackend, getTemplateSrv } from '@grafana/runtime';
 import { TpDataSourceOptions, TpQuery, TpVariableQuery } from './types';
 
 export class DataSource extends DataSourceWithBackend<TpQuery, TpDataSourceOptions> {
+  annotations = {};
+  
   constructor(instanceSettings: DataSourceInstanceSettings<TpDataSourceOptions>) {
     super(instanceSettings);
   }

src/plugin.json

@@ -7,6 +7,7 @@
   "backend": true,
   "streaming": true,
   "alerting": true,
+  "annotations": true,
   "executable": "gpx_timeplus",
   "info": {
     "description": "Timeplus is a unified streaming and historical data processing engine in a single binary. It helps data engineers and platform engineers solve complex real-time analytics use cases, and powers the Timeplus streaming analytics platform. The core engine is open-sourced at https://github.com/timeplus-io/proton. Timeplus Enterprise, https://www.timeplus.com/product, reduces time, complexity, and cost by using SQL to build real-time applications, data pipelines, and dashboards at the edge or cloud.",