This is the same type as what is spec'd. We cannot use a URL record
for this member as the spec in some scenarios will set and compare
the URL string to an invalid URL value, such as the empty string.
With implicit string constructors for the URL class removed
explicitly using URL::Parser::basic_parse makes the code look
quite silly in those places.
Resulting in a massive rename across almost everywhere! Alongside the
namespace change, we now have the following names:
* JS::NonnullGCPtr -> GC::Ref
* JS::GCPtr -> GC::Ptr
* JS::HeapFunction -> GC::Function
* JS::CellImpl -> GC::Cell
* JS::Handle -> GC::Root
The main motivation behind this is to remove JS specifics of the Realm
from the implementation of the Heap.
As a side effect of this change, this is a bit nicer to read than the
previous approach, and in my opinion, also makes it a little more clear
that this method is specific to a JavaScript Realm.
