This is meant to serve as the method all Ladybird chromes can use to
highlight the eTLD+1 substring of the URL. It uses the Public Suffix
List to break the URL into 3 parts: the scheme and subdomain, the
eTLD+1, and all remaining parts (port, path, query, etc.).
After d2c7e1ea7d, there is now only one
user of LibPublicSuffix - the URL sanitation utility within LibWebView.
Rather than having an entire library for the small Public Suffix data
accessor, merge it into LibWebView.
We currently implement several forms of this method across the Ladybird
chromes. As such, we see commits to add special URL handling that only
affects a single chrome. Instead, let's consolidate all special handling
in a single location for all chromes to make use of.
This method can handle resolving file:// URLs, falling back to a search
engine query, and validation against the Public Suffix List. These cases
were gathered from the various chromes.
