TimescaleDB was vulnerable to a privilege escalation attack in
the extension installation script. An attacker could precreate
objects normally owned by the extension and get those objects
used in the installation script since the script would only try
to create them if they did not already exist. Thanks to Pedro
Gallegos for reporting the problem.
This patch changes the schema, table and function creation to fail
and abort the installation when the object already exists instead
of using the existing object.
Security: CVE-2022-24128
