All Partition - HA feature
Currently, HA auto-discovery only support by partition state and control. 
But the MQTT interface can control all partition at once when the partition name is "all".

## Feature description
Here is my old "All partition" emulated mqtt control panel definition:
```yaml
alarm_control_panel:
  - platform: mqtt
    name: Full
    state_topic: 'paradox/states/partitions//current_state'
    command_topic: 'paradox/control/partitions/all'
    availability_topic: 'paradox/interface/availability'
    payload_disarm: 'disarm'
    payload_arm_home: 'arm_stay'
    payload_arm_away: 'arm'
    payload_arm_night: 'arm_sleep'
```
Maybe same can be published to the auto-discovery (the state_topic maybe aggregated from all partition to a `paradox/states/partitions/all`)
