Package C at_activate with csshnpd and modify luci-app-csshnpd to provide UI

[cpswan]

Is your feature request related to a problem? Please describe.

At present keys have to be manually created and copied to devices

Describe the solution you'd like

It should be possible to completely configure sshnpd from within LuCI.

[cpswan]

at_activate wasn't ready in PR99 so bumping to PR100

[cpswan]

C at_activate should be ready in PR 103

[cpswan]

Early testing of package based on c0.3.0:

root@Flint2:~# atactivate -h
Usage:
        Activate:       ./atactivate -a atsign -c cram-secret [-k atkeys filepath] [-r root-domain]

        New enrollment: ./at_auth_cli -a atsign -s otp/spp -p app_name -d device_name -n namespaces [-k atkeys filepath+filename to be store keysfile] [-r root-domain]

Notes:
        1) namepsaces list should follow format: "wavi:rw,buzz:r"
        2) root domain should follow format "root_domain:port"

The pieces are sliding into place

🙏 @XavierChanth and @srieteja
👀 @cconstab

[cpswan]

Presently blocked on atsign-foundation/noports#1666

Will continue work in PR104 once that's fixed.

[cpswan]

Now blocked by atsign-foundation/noports#1701

[cpswan]

at_activate enroll working manually with c0.4.2 release, so now need to wrap it with Luci and scripts.