Support get topic applied policy for DeduplicationStatus

[315157973]

Master Issue: #9216

Modifications

1. The api name of topic-level is consistent with that of namespace-level
2. Fix the problem that the namespace-level policy cannot be removed
3. Fix the problem that topic-level does not take effect when multiple levels of policy are set at the same time
4. Added applied API

Verifying this change

Verify that the new API is correct
Verify that the applied API is correct
Verify that policies of different levels exist at the same time and whether the priority is correct

[sijie]

@zymap Can you review it again?

[codelipenghui]

Looks good to me, could you please rebase the master branch?

[zymap]

LGTM