Library theming: Update Quickstarts extension in design kit

[patternfly-jira-sync]

Update the Quickstarts extension in the PatternFly design kit to align with the unified theme. Update Figma files, styles, documentation, and ensure unified visual consistency throughout.

Deliverables:

• Update tokens

• Include new variants

• Update branded icons

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Jira Issue: PF-3847

[patternfly-jira-sync]

Closed via Jira sync - Jira issue PF-3847 was closed.