[powergrid_usecase] Make InteractiveAI use Alerts or Alarm objects instead of just one

[ahmerique]

The concept of Alerts and Alarm are different in grid2op, right now only alarms are used. So changing to an environment which uses alerts would not be possible.

[ahmerique]

“Alert” used in grid2op is defined as follows:
An overload alert is displayed to the operator at T_alert, if – for any line l within the l_overload lines’ set – disconnection of l between T_alert and T_alert+ALERT_TIME_WINDOW leads to a “game over” (i.e. critical grid failure on the grid).
“Alarm” used in grid2op is defined as follow:
An alarm for the zone Z is displayed to the operator at T_alarm, if the overload of at least one line l of the zone Z leads to a game over between [T_alarm+X_steps ] and [T_alarm+X_steps+Z_steps ].