[Bug] Show error / message when Federal Admin attempts to assign an invalid role

[tbolt]

Description

Currently if a fed admin tries to assign a state that doesn't have a corresponding state admin certification letter it will fail silently. We will add an alert or feedback message notifying that the operation can't be completed.

Steps to reproduce

1. Login as fed admin
2. Attempt to assign a state admin to a user that doesn't have a certification

Expected results-

• Alert / message shown

Actual results-

• Nothing

Role Affected

• [ ] All
• [x] Federal Admin
• [ ] State Admin
• [ ] State Staff
• [ ] State Contractor
• [ ] System Admin

Environment

• [x] All
• [ ] PR #____
• [ ] Staging
• [ ] Production

Browser

• [x] All
• [ ] Firefox
• [ ] Chrome
• [ ] IE

Cypress test created OR Ticket for cypress test created-

Related user story/bug- (if applicable)

Additional information- (optional)

Logs or error output/Screenshot/Video- (at least 1 of these)