fix: return 404 when a dataset doesn't have attached policies

[ndr-brt]

WHAT

Backport upstream fix https://github.com/eclipse-edc/Connector/pull/4490 to 0.7.6, by using a response filter instead of copy-pasting all the module.

WHY

Briefly state why the change was necessary.

FURTHER NOTES

List other areas of code that have changed but are not necessarily linked to the main feature. This could be method signature changes, package declarations, bugs that were encountered and were fixed inline, etc.

Closes # <-- insert Issue number if one exists

[sonarcloud[bot]]

Quality Gate passed

Issues
2 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 SonarCloud

[atipijasin]

Amazing! Thx🚀