OTA update fault handling needs improvement

[Cabooman]

PROBLEM

When an OTA update fails for some reason, onOTAEnd() doesn't seem to be called, resulting in that we stay in an "updating" state with no CAN. The communicated state to the inverter is also UPDATING, so it's happy even though we're not updating any values from the battery BMS.

STEPS TO REPRODUCE

Start an OTA update, disconnect from wifi on the sending computer

PROPOSAL FOR SOLUTION

Implement an OTA timeout independent of the onOTAxxx functions, that restores CAN or performs a reset