fix(#9203): add facility_id backward compatibility in admin app

[Benmuiruri]

Description

Type casts users with existing string facility_id to Array facility_id that can be loaded in the edit form of the Admin app.

Closes #9203

Code review checklist

• Readable: Concise, well named, follows the style guide, documented if necessary.
• Documented: Configuration and user documentation on cht-docs
• Tested: Unit and/or e2e where appropriate
• Internationalised: All user facing text
• Backwards compatible: Works with existing data and configuration or includes a migration. Any breaking changes documented in the release notes.

Compose URLs

If Build CI hasn't passed, these may 404:

• Core
• CouchDB Single
• CouchDB Cluster

License

The software is provided under AGPL-3.0. Contributions to this project are accepted under the same license.

[latin-panda]

LGTM!

[Benmuiruri]

I'm going to merge this Jenni. Thanks for your contribution.