RequestInit's trait properties should default to js.undefined

[flavomulti]

There is a deprecation warning on RequestInit:

  @inline
  @deprecated("use `new RequestInit {}` instead", "0.9.7")
  def apply(method: js.UndefOr[HttpMethod] = js.undefined,

which says to use new RequestInit {}. However, there are no defaults on RequestInit so its impractical to use. RequestInit should look like:

trait RequestInit extends js.Object {
  var blah: js.UndefOr[Blah] = js.undefined
  ...
}

so that you do not have to specify every property in the trait.

[flavomulti]

Looks like there is PR for this already despite me searching for one :-) Closing.