[backport v2.8.next1] Add user retention admin interface

[rak-phillip]

Summary

This adds a new interface that allows admins to define user retention settings. User retention settings allow for a user to automatically deactivate or delete after not logging into Rancher for a defined duration.

Fixes #11312
Backports #11303

Occurred changes and/or fixed issues

• Adds a new button for modifying user retention settings to the Users & Authentication => Users page
• Only displays the button if the currently logged in user is a Rancher admin
• Clicking on the button will route the admin to a User Retention settings form
• In the User Retention Form, an admin can configure
  • Duration of inactivity to disable a user
  • Duration of inactivity to delete a user
  • A cron job to schedule the process to disable/delete a user
  • If the cron job performs a dry run
  • The default last login value for users who have not previously logged on

Technical notes summary

I started developing this component using defineComponent. I realized that I wasn't utilizing the options api after developing for a while, so I decided to give it a go with <script setup>.

Areas or cases that should be tested

We should test the new features with an admin user and a non-admin user. Non-admin users should not be able to access the new feature.

Areas which could experience regressions

N/A

Screenshot/Video

Checklist

• The PR is linked to an issue and the linked issue has a Milestone, or no issue is needed
• The PR has a Milestone
• The PR template has been filled out
• The PR has been self reviewed
• The PR has a reviewer assigned
• The PR has automated tests or clear instructions for manual tests and the linked issue has appropriate QA labels, or tests are not needed
• The PR has reviewed with UX and tested in light and dark mode, or there are no UX changes