Unit test for matching panda rate limits

[sshane]

When the user overrides, panda expects the down rate is at least as high as the rate limit, but up needs to be under the limit. Add a test like in panda, but add user overriding. Would have caught mismatch in commaai/openpilot#26934, or the panda PR that changed it, when bumped.

[sshane]

@adeebshihadeh do you think a good place for this is https://github.com/commaai/openpilot/blob/8d3e661f795260ebd708975105d98f1bdbbcf181/selfdrive/car/tests/test_models.py#L204 with fake actuators and driver torque?

Can start adding more cases like these for torque cars