Modules/ElectricFieldReader: re-add option to specify depletion_depth
I have noticed that sometimes it is easier to specify the depletion depth than a full-depletion voltage, especially for HV-CMOS sensors.
This MR re-adds the depletion_depth
parameter, checks that only this or the depletion voltage is given, and scales the thickness domain accordingly.
It also adds a new unit test with the feature enabled.