deduce automatically motor positon
It looks like for tomography motor position (rotation_angle) are defined in node_init/technique/scan/motor) as ["motor_name", "bliss_alias"]. If there is no bliss_alias then this will be ["motor_name", None]. The name we are interested on is "motor_name". It could be read on preprocessing (for standard tomo), store and reused instead of the H5_rotation_angle_keys provided in settings.
An update like the "detector_valid_names".