Add if active for SCIM

What does this MR do and why?

Seeing if the SCIM identity is active is important for troubleshooting SCIM identities.

This has been an ongoing issue, especially for our support team. While using the API is a workaround, it's not great.

Screenshots or screen recordings

Before	After

How to set up and validate locally

1. Visit /admin/users/USERNAME/identities.
2. Set up SCIM.
3. Ensure there is no existing user with the account email.
4. Add the user to the SCIM app.

Alternatively, you should be able to add a "dummy" entry through rails console.

MR acceptance checklist

This checklist encourages us to confirm any changes have been analyzed to reduce risks in quality, performance, reliability, security, and maintainability.

• I have evaluated the MR acceptance checklist for this MR.