[DT-3086] Remove validation enum for centers list

[kevinmarete]

Addresses

https://broadworkbench.atlassian.net/browse/DT-3086

Summary

This PR removes the validation enum for centers list which now allows any string to be submitted.

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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

[fboulnois]

👍