add netstat to nix

[metaclips]

Current behavior

Proposed changes

Checks

• All commits in this Pull Request are signed and Verified by Github.
• All commits in this Pull Request follow the Ockam commit message convention.
• There are no Merge commits in this Pull Request. Ockam repo maintains a linear commit history. We merge Pull Requests by rebasing them onto the develop branch. Rebasing to the latest develop branch and force pushing to your Pull Request branch is okay.
• I have read and accept the Ockam Community Code of Conduct.
• I have read and accepted the Ockam Contributor License Agreement by adding my Git/Github details in a row at the end of the CONTRIBUTORS.csv file in a separate pull request to the build-trust/ockam repository. The easiest way to do this is to edit the CONTRIBUTORS.csv file in the github web UI and create a separate Pull Request, this will mark the commit as verified.