Feat: Adds application managers to home screen controlled by env var

[Matte22]

resolves #1451
resolves #418

API:

1. getUsers operation ID gained a query param of 'privilege' whos values can be ["admin" , "create_collection"]. This will return users with the specified privilege.

Client

1. Adds an env var to control the display of app managers on the home page "STIGMAN_CLIENT_DISPLAY_APPMANAGERS"
2. Adds card on home screen that lists display names and emails of users with "admin" privilege.
3. Additionally adds new css which allows for the new card aswell as the "Welcome" card to be scrollable when content overflows.

[sonarqubecloud]

Quality Gate passed for 'nuwcdivnpt_stig-manager-client'

Issues
1 New issue
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.6% Duplication on New Code

See analysis details on SonarQube Cloud

[sonarqubecloud]

Quality Gate passed for 'nuwcdivnpt_stig-manager-api'

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
100.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud