Fixes #8761

Describe your changes

When an element is created with dg._block() the _form_data will be propagated from its parent, but when an element is created with a dg._enqueue it will not. This makes it so the current code to find a form will not be able to find the right form, so the easiest way is just making _enqueue propagate a form. ( current code to find the form: )

But this makes it so the element after being created has the proper _form_data, so the above code could just be

return this_dg._active_dg._form_data

I have also an alternative suggestion that i think might be much cleaner but i wanted a second opinion since it would mean deleting 2 tests. But i find that these tests are highly problematic, let's look:

no_form = st.empty()
with st.form("form"):
  st.write("hi")
  with no_form:
    st.form_submit_button("OK")

In here (run from origin/develop) the form_submit_button is erroneously thought to be in a form since the _current_form function checks the closest context, sees no form, goes to the next and sees a form, but the context does not reflect the actual structure, it should iterate the parents!
I know realistically no one writes an interface like this, but what happens when you run this piece of code is you get a submit button, outside of any form, and a form without a submit button inside it, instead of an exception.

So the cleaner alternative would be:

• Neither _block nor _enqueue propagate _form_data to every element
• Test test_is_in_form_true_when_dg_stack_has_form and test_is_in_form_false_when_dg_stack_has_no_form is deleted
• The _current_form function actually iterates the parents of the active_dg until it hits the form dg which has a _form_data
  Something like

dg = this_dg._active_dg

while dg is not None:
    if dg._form_data is not None:
        return dg._form_data
    dg = dg._parent

Which one works best?

GitHub Issue Link (if applicable)

Fixes #8761
@Asaurus1 @kmcgrady I'm tagging you two because i saw you were interested in the issue

Testing Plan

I have added 2 new unit tests that reflect the desired behavior in the mentioned issue (these tests fail on the current origin/develop branch)

Contribution License Agreement

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