A solid reactive handling of `initialValues`

[SirbyAlive]

Is your feature request related to a problem? Please describe. The two means to provide initialValues are not consistent on updates (eg: after a successful submit):

• config property initialValues ignores any updates after the initial call.
• input value prop visually reacts to updates but the underlying form data is not updated.

Describe the solution you'd like I would like the initialValues to accept an accessor in the shape of an accessor function:

initialValues: () => ({
  myField: data().myField,
})

That is evaluated in a solid-js createEffect. My current workaround is:

const { form, setInitialValues, reset } = createForm();

createEffect(() => {
  setInitialValues(data());
  reset();
});

Its benefits are:

• it does load a synchronous initial state
• it does react to subsequent changes to the initial state
• it does reset the dirty flag (which the prop value does not)
• it does update the underlying form data (which the prop value does not)

Cons:

• Still not consistent with the value behavour

This could easily be added to @felte/solid create-form, given that it is a behaviour that would be coherent with the rest of the project. But I fear this shortcuts behaviours from the core package.