[DT-3107, DT-3108, DT-3110, DT-3112, DT-3113] Add entity-scoped FSO endpoints and access-controlled FileStorageObjectService

[kevinmarete]

Addresses

https://broadworkbench.atlassian.net/browse/DT-3107
https://broadworkbench.atlassian.net/browse/DT-3108
https://broadworkbench.atlassian.net/browse/DT-3110
https://broadworkbench.atlassian.net/browse/DT-3112
https://broadworkbench.atlassian.net/browse/DT-3113

Summary

This PR introduces core API functionality for managing entity-scoped File Storage Objects (FSOs). It includes endpoints for uploading files, streaming file content, soft-deleting FSOs, and updating file categories. Additionally, it adds a centralized FileStorageObjectService to enforce consistent access control policies based on entity, category, and user roles across all FSO operations.

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[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
87.7% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud