Deferred: Rename `getStackHook` to `getErrorHook`

Deferred: Rename `getStackHook` to `getErrorHook`

Rename `jQuery.Deferred.getStackHook` to `jQuery.Deferred.getErrorHook`
to indicate passing an error instance is usually a better choice - it
works with source maps while a raw stack generally does not.

In jQuery `3.7.0`, we'll keep both names, marking the old one as
deprecated. In jQuery `4.0.0` we'll just keep the new one. This
change implements the `4.0.0` version; PR gh-5212 implements
the `3.7.0` one.

Fixes gh-5201
Closes gh-5211
Ref gh-5212