[legacy-framework] [Page template] Forward submit event from form to parent event handler

[wKovacs64]

Closes: N/A

What are the changes and their implications?

This updates the model form component template to forward the submit event from the generated onSubmit event handler to the parent so the parent has access to the event.

I ran into needing the event in the parent while updating the tutorial and rather than document how to do this part, I figured it would be better to just update the template since needing access to the event in the user's onSubmit handler is probably a common scenario.

Checklist

• Tests added for changes
• PR submitted to blitzjs.com for any user facing changes

[flybayer]

Great, thank you!