cmds_gnrc_netif: Support enabling/disabling lwIP netifs from gnrc_netif shell

[yarrick]

Contribution description

Similar to Linux, lwIP has separate link and interface statuses.
This change expose this in a netopt and updates gnrc ifconfig to show and set it.

I am not really happy with the NETOPT_ACTIVE name. Maybe NETOPT_STATE could be renamed to NETOPT_RF_STATE?

The code for setting up/down is not very nice. Not sure if link state will be controllable in lwIP - maybe for 6lowpan radios.

Testing procedure

Flash tests/pkg/lwip . Any traffic received while the interface is down is dropped.

> ifconfig
Iface  ET0  HWaddr: 24:0A:C4:E6:0E:9F  Link: up  State: up 
          L2-PDU:1500  Source address length: 6
          Link type: wired
          inet6 addr: fe80::260a:c4ff:fee6:e9f  scope: link
          
> ifconfig ET0 down
> ifconfig
Iface  ET0  HWaddr: 24:0A:C4:E6:0E:9F  Link: up  State: down 
          L2-PDU:1500  Source address length: 6
          Link type: wired
          inet6 addr: fe80::260a:c4ff:fee6:e9f  scope: link
          
> ifconfig ET0 up

Issues/PRs references

This only makes a difference when gnrc_netif ifconfig command is used. For that it depends on #19971 and an extra change like 7160ed9 to replace lwip netif with the gnrc version.

[miri64]

Looking good

[riot-ci]

Murdock results

✔️ PASSED

726e2eb sys/shell/gnrc_netif: Set lwIP netif state on up/down

Success	Failures	Total	Runtime
7937	0	7937	14m:38s

Artifacts

• Documentation preview

[miri64]

bors merge

[bors]

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• Murdock
• static-tests
• tools-build-success