Radio fields that cannot be correctly parsed should report on the failing field

[gaurav]

I ran into a problem with the VLMD tool recently: some fields in the input REDCap file didn't have a "Choices, Calculations, OR Slider Labels" value (because they had been redacted). This resulted in an exception being thrown by the _parse_field_properties_from_encodings() method called from mapradio():

healdata-utils/src/healdata_utils/transforms/redcapcsv/mappings.py

Lines 146 to 155 in 5080227

	def mapradio(field):
	"""
	RADIO - radio buttons with options
	Determined by "options" (ie Choices, Calculations, OR Slider Labels)
	"""
	# parse enum/encodings
	encodings_string = field[choices_fieldname]
	return _parse_field_properties_from_encodings(encodings_string)

To help figure out where the error in the input was, it would be helpful if this exception was caught so that the field name was reported, or even a check for the most common error case (an empty field):

    if not encodings_string:
        raise ValueError(f"Empty encodings string not allowed in radio field {field} with column {choices_fieldname}.")

(The same is also true of dropdown fields, see below.)

healdata-utils/src/healdata_utils/transforms/redcapcsv/mappings.py

Lines 136 to 144 in 5080227

	def mapdropdown(field):
	"""
	DROPDOWN
	dropdown menu with options
	Determined by "options" (ie Choices, Calculations, OR Slider Labels)
	"""
	encodings_string = field[choices_fieldname]
	return _parse_field_properties_from_encodings(encodings_string)