Consolidate input argument combination checking for EK80 data

[leewujung]

Right now we have 2 places that checks the combination of input argument for compute_Sv/Sp in terms of encode_mode and waveform_mode.

Here:

echopype/echopype/calibrate/api.py

Lines 39 to 55 in 2720812

	# TODO: consolidate the below block with simrad.py::check_input_args_combination()
	# Check on waveform_mode, encode_mode inputs, and assumption on single filter time
	if echodata.sonar_model == "EK80":
	if waveform_mode is None or encode_mode is None:
	raise ValueError("waveform_mode and encode_mode must be specified for EK80 calibration")
	check_input_args_combination(waveform_mode=waveform_mode, encode_mode=encode_mode)
	elif echodata.sonar_model in ("EK60", "AZFP", "AZFP6"):
	if waveform_mode is not None and waveform_mode != "CW":
	logger.warning(
	"This sonar model transmits only narrowband signals (waveform_mode='CW'). "
	"Calibration will be in CW mode",
	)
	if encode_mode is not None and encode_mode != "power":
	logger.warning(
	"This sonar model only record data as power or power/angle samples "
	"(encode_mode='power'). Calibration will be done on the power samples.",
	)

and in the function check_input_args_combination here:

echopype/echopype/echodata/simrad.py

Lines 13 to 49 in 2720812

	def check_input_args_combination(
	waveform_mode: str, encode_mode: str, pulse_compression: bool = None
	) -> None:
	"""
	Checks that the ``waveform_mode`` and ``encode_mode`` have
	the correct values and that the combination of input arguments are valid, without
	considering the actual data.
	Parameters
	----------
	waveform_mode: str
	Type of transmit waveform
	encode_mode: str
	Type of encoded return echo data
	pulse_compression: bool
	States whether pulse compression should be used
	"""
	if waveform_mode not in ["CW", "BB"]:
	raise ValueError("The input waveform_mode must be either 'CW' or 'BB'!")
	if encode_mode not in ["complex", "power"]:
	raise ValueError("The input encode_mode must be either 'complex' or 'power'!")
	# BB has complex data only, but CW can have complex or power data
	if (waveform_mode == "BB") and (encode_mode == "power"):
	raise ValueError(
	"Data from broadband ('BB') transmission must be recorded as complex samples"
	)
	# make sure that we have BB and complex inputs, if pulse compression is selected
	if pulse_compression is not None:
	if pulse_compression and ((waveform_mode != "BB") or (encode_mode != "complex")):
	raise RuntimeError(
	"Pulse compression can only be used with "
	"waveform_mode='BB' and encode_mode='complex'"
	)

The checks these code blocks perform are different, since one also deals with different sonar_models, but I think it would be cleaner to just have 1 function in the calibration subpackage to do this (check_input_args_combination shouldn't be in echodata/simrad.py).

[tomatotomata]

I was thinking of moving the shared waveform/encode validation into a small helper under calibrate, then having both calibration and Simrad beam selection call that one implementation. I will keep the existing messages and pulse-compression behavior intact, and add focused tests for the invalid combinations. Let me know what you think.