Previously, the charset of name "UTF-16BE/LE" would be checked against
when following standards to convert the charset to UTF-8, but in
reality, the charsets "UTF-16BE" and "UTF-16LE" should be checked
separately.
Co-authored-by: Jelle Raaijmakers <jelle@ladybird.org>
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
