fix(sidebar): log error when fetching items

We have an issue where we don't log extension errors. This issue has been caused by tricky

try{
  return getResultAsPromise();
} catch(e) {
  //
}

The problem with this statement is that we directly return the promise and even when the promise gets rejected, the catch block never gets executed.

The solution is to await the promise. This MR also introduces the eslint rule that will enforce awaiting promises in try/catch blocks.

outdated packaged extension

Packaged extension to try this change out:

Updated: gitlab-workflow-3.11.2.vsix (how to install)

Related to #308 (closed)