Sets up the basic infrastructure for the audio node graph and
implements the AudioNode `connect()` method with its related overides.
AudioNodes store vectors of AudioNodeConnections and
AudioParamConnections to represent links between nodes.
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