Disallow dlopen in ClickHouse Main Binary Due to Security Risks

Don't allow dlopen in the main ClickHouse binary, because it is harmful and insecure. We don't use it. But it can be used by some libraries for the implementation of "plugins". We absolutely discourage the ancient technique of loading 3rd-party uncontrolled dangerous libraries into the process address space, because it is insane. #41429 (Alexey Milovidov).