StandardNameTable enhancement

[daltonkell]

The CF StandardNameTable uses list comprehensions in a variety of places, e.g.

compliance-checker/compliance_checker/cf/util.py

Lines 276 to 279 in 380e16a

	# generate and save a list of all standard names in file
	self._names = [node.get('id') for node in self._root.iter('entry')]
	self._aliases = [node.get('id') for node in self._root.iter('alias')]
	self._version = self._root.xpath('version_number')[0].text

More efficient data structures, such as a set, could be used to improve lookup performance.