Implements #5311

[js802025]

• Added Sponsor, SponsorDomain, SponsorUser Resources.
• Added Nova Rule to verify user email is in valid domain names.

[jvogt23]

LGTM, confirm with a second opinion

[kberzinch]

Additional notes:

• Consider setting a policy to limit who can interact with these models
• Consider configuring index settings for these models, at a minimum displayedAttributes should be set to the primary key to minimize bytes on the wire
• Consider adding these models to the ImportAllModels command so they are indexed correctly

[js802025]

Which users should we limit access to?

[kberzinch]

The highest-level role for non-technical users is officer - https://my.robojackets.org/docs/admins/permissions-roles/

We typically create a new permission, attach it to the role, and then check the permission in the policy: see #4400 for a rough example

[kberzinch]

Some comments are also still outstanding from prior review

[kberzinch]

Please review and respond to open comments from prior reviews

[kberzinch]

Some notes from quick UI testing

[jvogt23]

LGTM