add cmnd/ payloads for screen and tile removal

[moinmoin-sh]

• tile "disable" has moved to "action":"disable"|"enable"

new cmnd/ payloads to remove screens and tiles

remove screen:

{
  "screens": [
    { "screen": 2, "action": "remove" }
  ]
}

remove tile:

{
  "tiles": [
    { "screen": 1, "tile": 2, "action": "remove" }
  ]
}

braking change : keyword "disable" for tiles removed new "action" disable / enable tile:

{
  "tiles": [
    { "screen": 1, "tile": 2, "action": "disable" | "enable" }
  ]
}

rules:

• removing a screen removes all tiles on this screen as well
• removing sreen 1 (Home Screen) technically removes screen 1 and creates an empty screen 1 (Home Screen)

closes #33 closes #40