`registerDistinguishableCallback` is called when widget has been destroyed causing an error.

[maier49]

Bug

Sometimes when registerDistinguisableCallback is called, the widget has been destroyed so childNodes[index] is undefined when its owningId is accessed, causing an error. According to @agubler , this happens because it's called during the idle callback and will only affect dev. We can move it to the raf to avoid the issue.
Package Version: 6.0.3-pre

Expected behavior:
No error

Actual behavior:

Error