Filter Organizations for RegionalAdmin User Type

[nickviola]

Filter Organizations for RegionalAdmin User Type

🗣 Description

Closes #23 Filter Organizations for RegionalAdmin User Type in UI to make sure that regionalAdmin user types don't see all organizations.

💭 Motivation and context

Leadership requests that regionalAdmin users shouldn't be able to see all organizations, but rather only organizations in their specific region.

🧪 Testing

Confirm that regionalAdmin user types don't see all organizations, but rather only orgs in their region?

✅ Pre-approval checklist

• This PR has an informative and human-readable title.
• Changes are limited to a single goal - eschew scope creep!
• All future TODOs are captured in issues, which are referenced
  in code comments.
• All relevant type-of-change labels have been added.
• I have read the CONTRIBUTING document.
• These code changes follow cisagov code standards.
• All relevant repo and/or project documentation has been updated
  to reflect the changes in this PR.
• Tests have been added and/or modified to cover the changes in this PR.
• All new and existing tests pass.

[schmelz21]

LGTM

[ameliav]

There's a linter error on line 22 to change == to ===. Besides that, looks good!

[ameliav]

Approved!