Split Operator and Management API into different Swagger files (#875)

* Split Operator and Management API into different Swagger files

Signed-off-by: Daniel Valdivia <18384552+dvaldivia@users.noreply.github.com>

* Linting

Signed-off-by: Daniel Valdivia <18384552+dvaldivia@users.noreply.github.com>

restapi/admin_users_test.go

@@ -516,7 +516,7 @@ func TestListUsersWithAccessToBucket(t *testing.T) {
 			}
 			return mockResponse, nil
 		}
-		return nil, errorGeneric
+		return nil, ErrorGeneric
 	}
 	type args struct {
 		bucket string