Region aggregation fails for wildcard variables

[phackstock]

This dict lookup fails because we don't have an exact match:

nomenclature/nomenclature/codelist.py

Lines 598 to 605 in c3ad7da

	def vars_default_args(self, variables: list[str]) -> list[VariableCode]:
	"""return subset of variables which does not feature any special pyam
	aggregation arguments and where skip_region_aggregation is False"""
	return [
	self[var]
	for var in variables
	if not self[var].agg_kwargs and not self[var].skip_region_aggregation
	]