updated imports in extension.ts

Author: Achal1607

vscode/src/extension.ts

@@ -62,7 +62,7 @@ import { asRanges, StatusMessageRequest, ShowStatusMessageParams, QuickPickReque
          ExecInHtmlPageRequest, SetTextEditorDecorationParams, ProjectActionParams, UpdateConfigurationRequest, QuickPickStep, InputBoxStep, SaveDocumentsRequest, SaveDocumentRequestParams
 } from './protocol';
 import * as launchConfigurations from './launchConfigurations';
-import { createTreeViewService, TreeViewService, TreeItemDecorator, Visualizer, CustomizableTreeDataProvider } from './explorer';
+import { createTreeViewService, TreeViewService, Visualizer } from './explorer';
 import { initializeRunConfiguration, runConfigurationProvider, runConfigurationNodeProvider, configureRunSettings, runConfigurationUpdateAll } from './runConfiguration';
 import { InputStep, MultiStepInput } from './utils';
 import { PropertiesView } from './propertiesView/propertiesView';