[Empty States] Defining the empty state

[laurenmrice]

Acceptance criteria

• Compare the guidance between Core, Product, and the workgroup. (This work was synthesized in #17554)
• Definition: Per of our own definition, what are empty states? With what we currently have in code/docs/kit, is this a pattern or is it a component? What do we want this to be and where should it live in our system?
• Alignment: Consider if the component is align left or centered
• Playback to design team and work group team your point of view of how we should take this forward.