feat(settings): add desktop Sync success card
Because: - We are updating pairing flows and want to land UI components / pages first. - Adds the desktop screen confirming the device connected. This commit: - Adds `packages/fxa-settings/src/pages/Pair2/Authority/SyncSuccess/index.tsx`. - Adds storybook stories for the page. - Adds l10n files and tests. Closes #FXA-14240