[SM-1293] Add endpoint to fetch secret's access policies (#4146)

* Add authz handling for secret access policy reads

* Add the ability to fetch secret access polices from the repository

* refactor response models

* Add new endpoint

src/Core/SecretsManager/AuthorizationRequirements/SecretOperationRequirement.cs

@@ -12,4 +12,5 @@ public static class SecretOperations
     public static readonly SecretOperationRequirement Read = new() { Name = nameof(Read) };
     public static readonly SecretOperationRequirement Update = new() { Name = nameof(Update) };
     public static readonly SecretOperationRequirement Delete = new() { Name = nameof(Delete) };
+    public static readonly SecretOperationRequirement ReadAccessPolicies = new() { Name = nameof(ReadAccessPolicies) };
 }