Fix problem with import errors not showing up for the user (microsoft#5185)

For #3958 Root cause was a promise not being waited on to force errors to come out. <!-- If an item below does not apply to you, then go ahead and check it off as "done" and strikethrough the text, e.g.: - [x] ~Has unit tests & system/integration tests~ --> - [x] Pull request represents a single change (i.e. not fixing disparate/unrelated things in a single PR) - [x] Title summarizes what is changing - [x] Has a [news entry](https://github.com/Microsoft/vscode-python/tree/master/news) file (remember to thank yourself!) - [ ] Has sufficient logging. - [ ] Has telemetry for enhancements. - [ ] Unit tests & system/integration tests are added/updated - [ ] [Test plan](https://github.com/Microsoft/vscode-python/blob/master/.github/test_plan.md) is updated as appropriate - [ ] [`package-lock.json`](https://github.com/Microsoft/vscode-python/blob/master/package-lock.json) has been regenerated by running `npm install` (if dependencies have changed) - [ ] The wiki is updated with any design decisions/details.

Author: rchiodo

news/2 Fixes/3958.md

@@ -0,0 +1 @@
+Fix problem with errors not showing up for import when no jupyter installed.

package-lock.json

@@ -101,9 +101,11 @@ export class HistoryCommandListener implements IDataScienceCommandListener {
  }
 
  // tslint:disable:no-any
- private listenForErrors(promise: () => Promise<any>) : Promise<any> {
+ private async listenForErrors(promise: () => Promise<any>) : Promise<any> {
+ let result: any;
  try {
- return promise();
+ result = await promise();
+ return result;
  } catch (err) {
  if (!(err instanceof CancellationError)) {
  if (err.message) {
@@ -117,7 +119,7 @@ export class HistoryCommandListener implements IDataScienceCommandListener {
  this.logger.logInformation('Canceled');
  }
  }
- return Promise.resolve();
+ return result;
  }
 
  private showInformationMessage(message: string, question?: string) : Thenable<string | undefined> {