feat(userInfo): implement persisting user info to support limited tokens

[kuangp]

Hey, I just made a Pull Request!

Part of BEP-0003 Fixes https://github.com/backstage/backstage/issues/24420

:heavy_check_mark: Checklist

• [x] A changeset describing the change and affected packages. (more info)
• [ ] Added or updated documentation
• [x] Tests for new functionality and regression tests for bug fixes
• [ ] Screenshots attached (for UI changes)
• [x] All your commits have a Signed-off-by line in the message. (more info)

[backstage-goalie[bot]]

Changed Packages

Package Name	Package Path	Changeset Bump	Current Version
@backstage/backend-app-api	packages/backend-app-api	patch	v0.7.6-next.3
@backstage/plugin-auth-backend	plugins/auth-backend	patch	v0.22.6-next.3

[sachingharge]

Any rough estimation on when this PR will be merged and part of release as it is affecting all our users (such as leaders, tech leads etc.) who are part of many ad groups?

[kuangp]

Hey @freben @Rugvip gentle nudge here - hoping to get this into the next release 🤞

[kuangp]

@freben made updates based on your feedback - thanks!

[kuangp]

@freben @Rugvip another nudge on this one since release is coming up soon 🙏

[kuangp]

@freben thanks for taking another look! updated accordingly

[github-actions[bot]]

Thank you for contributing to Backstage! The changes in this pull request will be part of the 1.28.0 release, scheduled for Tue, 18 Jun 2024.