Stepped Tracker validation states

[joshwooding]

### Checklist
- [ ] Density (HD, MD, LD, TD)
- [ ] Mode (Light, Dark)
- [ ] Fill (Primary, Secondary, Tertiary)
- [ ] State (Default, Hover, Selected/Active, Disabled, Read-only, Other)
- [ ] Controlled API
- [ ] UITK accessibility parity (screen reader + keyboard interactions)

### Deliverables
- [ ] Characteristics spec
- [ ] Interactions spec, where necessary
- [ ] In Code & Figma (Component + Guide)
- [ ] Supporting site documentation

### Features
- [ ] Validation states (Error warning)
- [ ] Modify step

[origami-z]

Should be covered in #2886

[mark-tate]

Zazu Goal: S(3)

• changing prop names, deprecate old prop, add new
• docs updated on site

[tomhazledine]

• 2024-06-27 Discussed naming in FED meetup - unresolved
• 2024-06-28 Discussion in Teams ("let's name a prop"): consensus on adding stage and status props and merging state in-component.
• 2024-07-01 Waiting on @joshwooding for final sign-off on interaction of activeStep with state (see Teams thread)

[tomhazledine]

#3584 ready for dev review

[tomhazledine]

Addressing review comments re: stories and examples.

[mark-tate]

Can we close out by 23/07/24 @joshwooding

[tomhazledine]

Approved and merged