Support for multiple networks in various flyctl subcommands

Looks like flyctl is missing some features for managing multiple networks:

  • List networks in the current organization
  • Tell which network an app belongs to
  • Specify a network ID for flyctl ssh and flyctl wireguard

I’m able to patch some subcommands like flyctl wireguard create to accept a network ID but it seems that larger changes are needed for subcommands that depend on CLI/agent communication (e.g. flyctl ssh console).