feat: add ratio between full page content and sent content for prompt

[Patai5]

https://console.apify.com/actors/paOtbjvyUiNsr1Qms/issues/1UwwGC0Q7bWJgZchB

For websites with a lot of content, the information in sentContent doesn't include all the information from the page.
Would it be possible to introduce some indicator of not the content from whole page was used?
Possibly some ratio of value between 0 and 1 - like 0.64 = 64% of the generated markdown was sent/used for the prompt.
This would help us to investigate issues related to the content was cutoff in the middle and therefore right results were not provided to the dataset.

[PavlinaVencovska]

@JJetmar Can we have a hint or priority in here as well, please

[JJetmar]

@PavlinaVencovska Nice to have is ok, we know about this limitation and we can detect now manually on small Runs.