feat(data-service): expose close event VSCODE-536 (#5849)

* feat(data-service): expose serverClosed event VSCODE-536

* fest: listen on client close

* refactor: bump log id

* refactor: without disconnect

packages/data-service/src/data-service.ts

@@ -138,6 +138,7 @@ export type ExplainExecuteOptions = ExecutionOptions & {
 export interface DataServiceEventMap {
   topologyDescriptionChanged: (evt: TopologyDescriptionChangedEvent) => void;
   connectionInfoSecretsChanged: () => void;
+  close: () => void;
 }
 
 export type UpdatePreviewChange = {
@@ -1017,7 +1018,7 @@ class DataServiceImpl extends WithLogContext implements DataService {
   }
 
   once(...args: Parameters<DataService['on']>) {
-    this._emitter.on(...args);
+    this._emitter.once(...args);
     return this;
   }
 
@@ -2276,6 +2277,11 @@ class DataServiceImpl extends WithLogContext implements DataService {
         });
       });
 
+      client.on('close', () => {
+        this._logger.info(mongoLogId(1_001_000_315), 'Client is closed');
+        this._emitter.emit('close');
+      });
+
       client.on('serverClosed', (evt: ServerClosedEvent) => {
         this._logger.info(mongoLogId(1_001_000_020), 'Server closed', {
           address: evt.address,