fix(freebsd): correct configuration of IPv6 routes

[frikilax]

Proposed Commit Message

fix(freebsd): correct configuration of IPv6 routes

the generation of IPv6 routes on FreeBSD were not correct.
This commit keeps the generation of IPv4 routes as they were, but introduces a change to parameter names and separate handling of IPv6 routes

Additional Context

This only impacts Networking Config v1 on FreeBSD, and nothing was changed regarding other *BSD distros.

Test Steps

Checklist

• [ ] My code follows the process laid out in the documentation
• [ ] I have updated or added any unit tests accordingly
• [ ] I have updated or added any documentation accordingly

Merge type

• [x] Squash merge using "Proposed Commit Message"
• [ ] Rebase and merge unique commits. Requires commit messages per-commit each referencing the pull request number (#<PR_NUM>)