Clean up global-organization-override

[stephenkao]

Problem statement

We maintain a global-membership-state value in LocalStorage for the current user's Organization and a global-organization-override value for impersonated Organization. However, since both values are updated upon impersonation, it may be redundant to maintain both values instead of just using the global-membership-state.

At the moment, it doesn't seem to help us to maintain two separate values, especially since we use memberType to determine UI visibility across the site.

What you need to know

• Override value is set upon authentication here: https://github.com/CDCgov/prime-reportstream/blob/master/frontend-react/src/hooks/UseOktaMemberships.ts#L167
  (Note for the future: Can we simplify the reducer logic or even remove the reducer entirely? Does it need to be a reducer?)

Acceptance criteria

• Investigate whether or not global-organization-override can be removed safely
  • If so, remove global-organization-override logic
  • If not, document why not on this ticket and communicate out to engineering team