This URL library ends up being a relatively fundamental base library of
the system, as LibCore depends on LibURL.
This change has two main benefits:
* Moving AK back more towards being an agnostic library that can
be used between the kernel and userspace. URL has never really fit
that description - and is not used in the kernel.
* URL _should_ depend on LibUnicode, as it needs punnycode support.
However, it's not really possible to do this inside of AK as it can't
depend on any external library. This change brings us a little closer
to being able to do that, but unfortunately we aren't there quite
yet, as the code generators depend on LibCore.
Which pretty much needs to be done together due to the amount of places
where they are compared together.
This also involves porting over StackOfOpenElements over to FlyString
from DeprecatedFly string to prevent a gazillion calls to
`.to_deprecated_fly_string` calls in HTMLParser.
This tokenizes a page's source to produce HTML with syntax highlighting.
The first implementation here is rather simple; we do not yet implement
code folding, line numbers, etc.
The goal is for this to be used as the View Source implementation for
all Ladybird chromes.
