Summary:
The github commit https://github.com/yugabyte/yugabyte-db/commit/8710fe7f3d0b7b8ba61627ef7d291ca577f7c06f incorrectly uses kNamespaceName as db name in cdcsdk_ysql_query_api-test instead of test_namespace_name, causing the master build to fail (error: use of undeclared identifier 'kNamespaceName'). kNamespaceName was removed in #31965, which switched CDCSDK tests to the test_namespace_name member. Correcting all 6 occurrences in this revision.

Original commit: 8710fe7 / #30764

Test Plan: unit test

Reviewers: ssharma, gaurav.singh, skumar

Reviewed By: ssharma

Subscribers: ycdcxcluster

Differential Revision: https://phorge.dev.yugabyte.com/D54960