now dotview requests are canceled when the window is closed

src/dotViewer.ts

@@ -4,6 +4,7 @@ import { client, clientReady, disposalQueue, extensionUri, resultHandlers } from
 import * as fs from "fs";
 import { ParameterDefinitions, getNonce, ResultNotification, ParameterDefinition } from './utils';
 import { CancellationTokenSource } from 'vscode';
+import { ParameterInformation } from 'vscode';
 
 
 export namespace DotViewer {
@@ -107,6 +108,9 @@ export namespace DotViewer {
             this.panel.onDidDispose(() => {
                 vscode.commands.executeCommand('setContext', 'modest:dotViewFocused', false);
                 LiveDotView.liveDotViews.delete(this.fileUri);
+                if (this.lastRunToken) {
+                    client?.sendRequest("modest/cancelRun", { runToken: this.lastRunToken });
+                }
             });
 
             this.panel.onDidChangeViewState(