Second attempt to #93010

This streamlines passing Promise/Task from two cross-boundary calls per promise argument to one.

• none when it's passed
• one when it's resolved, rejected or garbage collected

Changes

• drop create_task_callback
• simplify complete_task
• simplify mono_wasm_marshal_promise and rename it to mono_wasm_resolve_or_reject_promise
• introduced GCVHandle
  • it's like GCHandle in that it keeps proxy of C# object alive while JS owns it.
  • but it's allocated ahead of time on JS side
• introduced JSVHandle
  • it's like JSHandle in that it keeps proxy of JS object alive while C# owns it.
  • but it's allocated ahead of time on C# side
• improved GetTaskResultDynamic to handle void Task
• introduced internal JSObject.DisposeLocal
  • we can dispose both sides during resolve/reject call without extra dispose call

Interop "stack frame"

• fixed IntPtr and handles to be I32 rather than U32
• changed MarshalerType from I32 to U8 size
• added MarshalerType.TaskResolved and MarshalerType.TaskRejected
  • this allows us to pass better metadata in the same JSMarshalerArgument slot
• moved JSMarshalerArgument.ElementType to different offset
  • to not clash with handles
• JSMarshalerArgument.ElementType now contains type of the promise's result
  • this is necessary for marshaling with dynamic type
• changed JSBindingType layout accordingly.
  • In future this could also help with nested generic types.
• bumped schema version to 2

Other

• better type for WeakRefInternal<T>
• interop unit test no longer ForceDisposeProxies in the middle of the program because it can't balance C# side of handles