improve skywire-cli proxy command

[mrpalide]

Did you run make format && make check? Yes

Fixes #1675 #1682

Changes:

• reimplement skywire-cli proxy status output
• improve skywire-cli proxy stop command by add two flags --all and --name
• reimplementation skywire-cli proxy start command
• add ctrl+c signal to skywire-cli proxy start and skywire-cli vpn start commands

How to test this PR:

• build skywire at this branch and run a visor
• run skywire-cli proxy status for check status of proxies that available in skywire-config.json file
• run proxy and check status command again
• add new custom proxy to config like this: skywire-cli proxy start --name uk-proxy --pk 0216f90f998b11e83b0fa8eb76e5ba03c5dd72ab68432264f37e282f704992cd9f --addr :9090. By this command, we trying to add new custom proxy named uk-proxy with -srv flag as PubKey we use here 0216... and -addr flag as port available for proxy 127.0.0.1. Check status of proxies by skywire-cli proxy status again after running custom proxy.
• skywire-cli proxy stop --name uk-proxy will stop uk-proxy. If you want stop all running proxies use --all flag as skywire-cli proxy stop --all
• use arbitrary PK and start proxy or vpn, then trying ctrl+c shutdown signal shortcut.

[0pcom]

$ git clone https://github.com/mrpalide/skywire
Cloning into 'skywire'...
remote: Enumerating objects: 71769, done.
remote: Counting objects: 100% (4658/4658), done.
remote: Compressing objects: 100% (2561/2561), done.
Receiving objects:  91% (65458/71769), 37.00 MiB | 1.91 MiB/s/s
remote: Total 71769 (delta 1958), reused 4421 (delta 1859), pack-reused 67111
Receiving objects: 100% (71769/71769), 64.03 MiB | 1.32 MiB/s, done.
Resolving deltas: 100% (45034/45034), done.
$ cd skywire
$ git checkout feat/add-multiple-proxy-command-to-skywire-cli-proxy
branch 'feat/add-multiple-proxy-command-to-skywire-cli-proxy' set up to track 'origin/feat/add-multiple-proxy-command-to-skywire-cli-proxy'.
Switched to a new branch 'feat/add-multiple-proxy-command-to-skywire-cli-proxy'
$ sudo go run cmd/skywire-visor/skywire-visor.go -p --loglvl debug
...

$ skywire-cli proxy status
stopped
$ skywire-cli proxy list
03483a9eb478af76ecae7d0256118a1e2fac8c799f9fd51aebf92b1f8f96edf1c5:3 | ID
03894b70efab29edcb5669cda5c34e47a6efce9130849faeaac4c3776e69d7b152:3 | ID
03a934a4d3780ba3c9d91619faa36153041373bd6ce4ea57b0e9aeceb7f6771940:3 | SE
02071414e3ed2e595a70a414e05c6d9836a6d1d94793ededaa3bb248bfaf79d236:3 | ID
031e98c8306c98ad478bd45defbc84e2199b2a29fabc296609bd1e4a0e7d2c6e5e:3 | ID
039f7fb8e491aac08411ace482da85ba0147d13ca73d9b86f8c50f84c4fb812230:3 | ID
...

$ skywire-cli proxy start 0250e4d1b39a0360fb5d888324b8062bf57198a6fa5d7dda943b682652870b0a43
Starting...............................................
Running!
$ skywire-cli proxy status
running

$ go run cmd/skywire-cli/skywire-cli.go proxy start --pk 02bb45a0619f21fdee58a917032e36b6151e019388cbc4e5252f25bc2601f80994 --name us-proxy --addr :1081
Starting..
Running!
$ go run cmd/skywire-cli/skywire-cli.go proxy status
---- All Proxy List -----------------------------------------------------

Name: skysocks-client
Status: running
Server: 0250e4d1b39a0360fb5d888324b8062bf57198a6fa5d7dda943b682652870b0a43
Address: 
AppPort: 13
AutoStart: false

Name: us-proxy
Status: running
Server: 02bb45a0619f21fdee58a917032e36b6151e019388cbc4e5252f25bc2601f80994
Address: 127.0.0.1:1081
AppPort: 51
AutoStart: false

-------------------------------------------------------------------------
$ go run cmd/skywire-cli/skywire-cli.go proxy status --json
{
  "output": [
    {
      "name": "skysocks-client",
      "status": "running",
      "autostart": false,
      "args": [
        "-srv",
        "0250e4d1b39a0360fb5d888324b8062bf57198a6fa5d7dda943b682652870b0a43"
      ],
      "app_port": 13
    },
    {
      "name": "us-proxy",
      "status": "running",
      "autostart": false,
      "args": [
        "-srv",
        "02bb45a0619f21fdee58a917032e36b6151e019388cbc4e5252f25bc2601f80994",
        "-addr",
        ":1081"
      ],
      "app_port": 51
    }
  ]
}

$ curl -Lx socks5://127.0.0.1:1081 http://ip.skycoin.com/ | jq
  % Total    % Received % Xferd  Average Speed   Time    Time     Time  Current
                                 Dload  Upload   Total   Spent    Left  Speed
100     5  100     5    0     0      6      0 --:--:-- --:--:-- --:--:--     6
100   302  100   302    0     0    150      0  0:00:02  0:00:02 --:--:--   843
{
  "ip_address": "98.211.135.222",
  "latitude": 26.6165,
  "longitude": -80.0444,
  "postal_code": "33460",
  "continent_code": "NA",
  "country_code": "US",
  "country_name": "United States",
  "region_code": "FL",
  "region_name": "Florida",
  "province_code": "",
  "province_name": "",
  "city_name": "Lake Worth",
  "timezone": "America/New_York"
}
$ curl -Lx socks5://127.0.0.1:1080 http://ip.skycoin.com/ | jq
  % Total    % Received % Xferd  Average Speed   Time    Time     Time  Current
                                 Dload  Upload   Total   Spent    Left  Speed
100     5  100     5    0     0      3      0  0:00:01  0:00:01 --:--:--     3
100   302  100   302    0     0     80      0  0:00:03  0:00:03 --:--:--   151
{
  "ip_address": "208.78.41.141",
  "latitude": 49.2825,
  "longitude": -123.1291,
  "postal_code": "V6E",
  "continent_code": "NA",
  "country_code": "CA",
  "country_name": "Canada",
  "region_code": "BC",
  "region_name": "British Columbia",
  "province_code": "",
  "province_name": "",
  "city_name": "Vancouver",
  "timezone": "America/Vancouver"
}

$ go run cmd/skywire-cli/skywire-cli.go proxy stop --all
all skysocks clients stopped
$ go run cmd/skywire-cli/skywire-cli.go proxy status
---- All Proxy List -----------------------------------------------------

Name: skysocks-client
Status: stopped
Server: 0250e4d1b39a0360fb5d888324b8062bf57198a6fa5d7dda943b682652870b0a43
Address: 
AppPort: 13
AutoStart: false

Name: us-proxy
Status: stopped
Server: 02bb45a0619f21fdee58a917032e36b6151e019388cbc4e5252f25bc2601f80994
Address: 127.0.0.1:1081
AppPort: 51
AutoStart: false

-------------------------------------------------------------------------

Works great! Tremendous work, and something we really needed.

I will update the proxy documentation with this once merged, Thanks so much @mrpalide!