doc: clarity type of first argument in zlib
The current documentation for Convenience Methods specify that first argument can be string or buffer, string or raw Buffer.
This PR replace string and raw Buffer to string or buffer.
Do not update/delete: Banner broadcast message test data
Do not update/delete: Notification broadcast message test data
The current documentation for Convenience Methods specify that first argument can be string or buffer, string or raw Buffer.
This PR replace string and raw Buffer to string or buffer.