In an SSH tunnel, use a proxy

When I used the SSH tunnel function, I found that the test connection could not pass, and I could connect to it normally by using other SSH connection tools. After investigation and analysis, ssh tunnel function in DBeaver lacks proxy. Moreover, I also found that even if the Network Connections in DBeaver configured or obtained the system proxies, these proxies did not take effect in the SSH tunnel. Therefore, I hope to add a function to meet more application scenarios, and finally I hope that DBeaver will be better ~