FEATURE: Implement check the availability of website / detection of parked & for sale domains

## Description

I have been thinking about it even before I've found this: https://github.com/StevenBlack/hosts/issues/1613#issuecomment-820162550 @AdKiller

As many as dead (non-existent domain etc) domains, there are many parked / for sale zombie domains, which still do exist but are dead at the same time...: "This domain is for sale", "Website is no longer available", currenlty PyFunceble marks such domain as ACTIVE...but PyFunceble could have an option to check whether a real website exists on the domain and mark it "REAL" if not, then "ZOMBIE" label.

## Possible Solution

Such feature:
- would require downloading a domain's main body and searching in the body for text phrases like: "for sale", "no longer available", "rent domain" etc,
- could lead to some false positives
- a pity there is no status code for it: https://en.wikipedia.org/wiki/List_of_HTTP_status_codes, would not require downloading the whole site's body and searching for text phrases

## Screenshoot