[DT-2851] Fix async spinner button

[fboulnois]

Addresses

https://broadworkbench.atlassian.net/browse/DT-2851

Summary

Currently, when clicking the AsyncSpinnerButton, no spinner is shown on long-running actions. This means the user gets no feedback that an operation is in progress. This fixes that issue, and adds a test to avoid regressions.

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[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

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

See analysis details on SonarQube Cloud

[rushtong]

👍🏽