(web-scraper): Max result records counts processed pages, not results

[barjin]

As reported in a user issue, returning undefined from the Page Function still fires a request to the Dataset API (adding no item) and counts towards the Max result records (maxResultsPerCrawl) crawler limit.

With the limit set to e.g. 10 and pageFunction returning undefined on every other request, the Actor will finish with 5 dataset items only (will stop prematurely, since the "limit has been hit").

This seems like a bug to me, so I'd fix it regardless of whether it's breaking.

Reproduction scenario here: https://console.apify.com/view/runs/T3XtWRqfhCSFUeH7X

edit: this is likely the case with other generic Actors as well.