Allow calling identifyUserWithUserId multiple times

[jsedlacek]

If called second time:

• If the survey is already shown, do nothing
• If the survey is not shown, but /api/widget request already in progress, cancel previous request and perform a new request with new data
• Otherwise perform a new request with new data and show widget according to the result of it

[jsedlacek]

The following still does not work:

• If the survey is not shown, but /api/widget request already in progress, cancel previous request and perform a new request with new data

It processes the first request, and the second is not triggered.