Library theming: Update Empty states component in design kit

[andrew-ronaldson]

Refresh the Empty states component within the PatternFly design kit per the unified theme initiative. Update assets, Figma files, and documentation so the component is visually consistent with new theme direction.

Deliverables:

• Update tokens

• Include new variants

• Update branded icons

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Jira Issue: PF-3677

[patternfly-jira-sync]

Closed via Jira sync - Jira issue PF-3677 was closed.