Send more detailed event feedback data

[okahilak]

Event feedback messages currently contain ID and error code. Some possible fields to add:

• Time of starting event execution
• Time of finishing event execution

Possible event-type specific information (useful in case of pulse, charge, and discharge events):

• Capacitor voltage before event execution
• Capacitor voltage after event execution

In case of pulse events, the voltages can be used to check that the pulse was given successfully (the voltages need to drop enough from before to after). In case of discharge/charge events, the voltages can be used to check that the target voltage was reached.

• If an event is late, send information about how late it was.