"Unassign Texts for User" does not complete when suspending a user

[kohlee]

Describe the bug
After suspending a user, a dialog box prompts "Unassign texts for user?"
When NO is selected, the box disappears. When YES is selected, there is no indication that an unassign job is running or that the YES selection has been recognized.

To Reproduce
Steps to reproduce the behavior:

1. From People, suspend a user
2. From dialog box "Unassign texts for user," select YES
3. See no changes

Expected behavior
User expects an indication that YES has been selected (e.g. greyed out "Working...) and to receive a success message when the job completes or an error message if it fails.

Additional context
This bug was reported on an organization with a large number of messages and campaign contacts. Adding a toggle for unarchived/archived texts or just limiting the operation to unarchived campaigns could meet the need.

[bchrobot]

• Add a "working..." state using a progress spinner (see https://v4.mui.com/components/progress/#interactive-integration) while request completes.
• Add an <Alert> to the dialog if the operation errors.