[User Feedback] Can't scroll after submitting or cancelling using createForm

[c298lee]

Description

This appears to be an issue specifically with the createForm method, rather than the attachTo method. For attachTo, the form is constructed with overridden values for onFormClose and onFormSubmitted passed which trigger resetting the body overflow, but when using createForm / appendToDom, no overridden values are passed for close / success (see integration.ts:315 compared to integration.ts:232), so onFormClose and therefore dialog.close() are never called and style="overflow: hidden;" is never removed.

I'm wondering if the real issue is that the default options _options specify onFormClose and onFormSubmitted but these values appear to be undefined rather than a default value?

Switching to attachTo resolved the issue, but I believe this should be resolved in createForm as well.

Related to #12496

[c298lee]

Fixed with #13203