BYD Atto 3: Make startup less prone to throw Events

[dalathegreat]

What

This PR makes the Atto 3 less likely to throw Events the first seconds on startup

Why

Feedback from flying tools video on the Atto 3, which reports CELL DEVIATION and UNDERVOLTAGE as soon as the battery starts.

How

The issue was split into two parts

• Cell max/min values where updated async during OBD2 polling, causing the min to actually be larger than max for a few seconds. By adding ABS subtraction to compare the diff, we catch this edge case
• Pack undervoltage on startup. Due to the Datalayer having 370.0V as startup value, which is 10V lower than the Atto 3 minimum voltage (380.0V), we now init the value to 380.1V to avoid false positive events.