Hyperion: UDC default state should start robot soaking early

Most of the time the slowest step when first passing the baton to UDC is waiting for the robot to cool down. At the moment we don't explicitly tell the robot to soak but instead once we get to robot load the robot will soak itself first. We can gain quite a bit of speed by explicitly triggering a soak early in the UDC default state.

We need to do this after we have done the unload of any pin left up from before UDC default state as this could be a warm pin

Note: In general, we don't care about the speed of first starting UDC as we don't do it often but if we can get quick wins easily then there's no harm.

## Acceptance Criteria
- UDC default state soaks the robot early but after pin unload

Locate the UDC default state and the existing unload operation for any pin left from before that state. Trace how robot soaking is requested when robot load begins, then ensure the default state requests soaking only after pin unload; done means the acceptance criterion is met without changing the stated UDC startup behavior.

Written by the indexing model from the issue text.