Alarm Control Panel: Complete On_... triggers

**Describe the problem you have/What new integration you would like**
Add armed_away, armed_home, disarmed, pending triggers. (any trigger that is missing for possible states)

**Please describe your use case for this integration and alternatives you've tried:**

This would allow users to turn on LEDS to indicate states, send HTTP requests per state, sound a buzzer to indicate progress of setting (ARMING --> ARM_*)

``` on_state:
then:
- delay: 2s
- if:
condition:
alarm_control_panel.is_armed: alarm_panel
then:
- script.execute: set_beep # beep to indicate the alarm is set
```
Above example works fine, but a NOT version for detecting disarmed state does not.

**Additional context**

Start by locating the alarm_control_panel on_state trigger handling and the alarm_control_panel.is_armed condition referenced in the issue. Check how armed_away, armed_home, disarmed, and pending states are represented, then verify that each requested state can trigger the documented actions and that disarmed detection works without relying on a NOT condition.

Written by the indexing model from the issue text.