fix(WizardContext - next): Don't initialize 'currentFooter' to avoid stale props

[jpuzz0]

Describe the problem
When users want to use local state in the same component as Wizard, and pass that updated state to that Wizard's footer, when that footer is a React element, the local state change is not leading to the state updating in that footer. There are workarounds for this specific use-case mentioned below.

Expected behavior
When using local state in the same component that renders Wizard and specifically a Wizard with a custom footer that is a React element, state changes should be reflected within that footer.

Is this issue blocking you?
Not a blocker. Users can pass a footer as a function that returns a react element or use context wrapped around the Wizard to manage state that is accessible from a custom wizard footer.