More "network update" options

[famfo]

Feature request description

I would like to have more options to update an existing network than just adding and removing DNS entries. For example:

• adding a new subnet / gateway
• removing a subnet / gateway
• enable IPv6 networking

Suggest potential solution

To have the podman network update command include all / most of the options podman network create to update existing networks.

Have you considered any alternatives?

A command to edit the network definition file directly with $EDITOR with some simple docs in a comment.

Additional context

The default network doesn't have IPv6 support so I need to edit it on all my setups.