fix: expose user/password command line options

[spena]

Description

Exposes the --user/--password command-line options when executing ksql --help. I don't know why they were hidden if there is nothing to secure by hiding them.

Testing done

Verify ksql --help exposes the parameters:

> ksql --help
...
--password <password>, -p <password>
            If your KSQL server is configured for authentication, then provide
            your password here. The username must be specified separately with
            the -u/--user flag
...
--user <userName>, -u <userName>
            If your KSQL server is configured for authentication, then provide
            your user name here. The password must be specified separately with
            the -p/--password flag
...

Reviewer checklist

• Ensure docs are updated if necessary. (eg. if a user visible feature is being added or changed).
• Ensure relevant issues are linked (description should include text like "Fixes #")

[rodesai]

LGTM