Add NO_PROXY env var to the lab nodes by default

[hellt]

When http proxy is in place to access internet resources containerlab users typically have to set the http_proxy/https_proxy env vars in their topologies to make the applications running in the containers use the proxy:

name: anysec-macsec

mgmt:
  network: anysec
  ipv4-subnet: 172.50.50.0/24

topology:
  kinds:
    linux:
      image: ghcr.io/srl-labs/network-multitool
      env:
        http_proxy: ${http_proxy}
        https_proxy: ${https_proxy}
        no_proxy: pe1,pe2,p3,p4,ce5,ce6,client7,client8,gnmic,prometheus,grafana,localhost,172.50.50.0/24

Note, how every lab node, lab mgmt network and localhost has to be called out in the no_proxy env var to ensure that the nodes when communicating with each other will not try to reach the proxy.

Containerlab should set these values automatically as a default env var set:

• all node names as provided in the topology
• mgmt network
• localhost
• 127.0.0.1
• *.local addresses

[toweber]

Would really love to see this feature implemented!
Subnet ranges do not work with the no_proxy variable for some OS. Hostname wildcards can be used, but IP addresses should also be added individually not only via CIDR.

Edit: Might deliver a PR myself in the coming days 😄