Library theming: Update Login page pattern in design kit

[patternfly-jira-sync]

Update the Login page pattern 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

• Address audit fixes:

• Boolean inconsistency updates (checklist here)

• Fix text wrapping (login card text is wrapping on the invalid=false when the language selector boolean is turned on)

---

Jira Issue: PF-3922