Fix: Make VehicleReponseModel values optional

[CM000n]

Interestingly, there are probably vehicles / accounts where the endpoints did not even return basic information to the car.
See DurgNomis-drol/ha_toyota#211

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Comparison is base (2c133e0) 70.50% compared to head (4cc1458) 70.50%.

Additional details and impacted files

@@           Coverage Diff           @@
##           master     #307   +/-   ##
=======================================
  Coverage   70.50%   70.50%           
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  Files          30       30           
  Lines        1434     1434           
=======================================
  Hits         1011     1011           
  Misses        423      423           

Flag	Coverage Δ
unittests	70.50% <100.00%> (ø)

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[CM000n]

Thx for the approval. I will wait with the merge till I get some more info from the User in the corresponding issue

[CM000n]

I am closing this because the error is not on our side.
The cause was probably a faulty/incomplete migration of the user vehicle to the new API: DurgNomis-drol/ha_toyota#211 (comment)