WIP WebIDL to wit convertor.

Conversions of types from WebIDL to wit.

WebIDL type	wit type
any	❓
undefined	just leave it out
boolean	bool
byte	s8
octet	u8
short	s16
unsigned short	u16
long	s32
unsigned long	u32
long long	s64
unsigned long long	u64
float	f32
unrestricted float	f32
double	f64
unrestricted double	f64
bigint	❓
DOMString	string
ByteString	string
USVString	string
object	❓
symbol	❓
interface	resource or interface
callback interface	❓
dictionary	record
enum	enum
callback	func
constructor	constructor
T? (optional)	option<T>
sequence<T>	list<T>
record<K, V>	A custom resource
Promise<T>	❓
or (union)	variant
Buffer types (e.g. Int8Array)	A custom resource
FrozenArray<T>	list<T>
ObservableArray<T>	❓
setlike<T>	Add set methods
maplike<K, V>	❓
namespace	resource or interface
typedef	type
const	A getter

❓ = Not yet sure how to deal with this type.