Replacement for python2 `cmp` functions

[wxtim]

During the conversion from python2 to 3 @wxtim has used:

-cmp(a, b)
+(a>b) - (a<b)

in

• lib/python/rose/config.py
• lib/python/rose/macro.py
• lib/python/rose/namelist_dump.py
• lib/python/rose/suite_clean.py

This is subtracting booleans, which is ugly and non-intuitive.

Additionally this logic is used in functions called thus:

-list_.sort(sort_function)
+from functools import cmp_to_key
+list_sort(key=cmp_to_key(sort_func)

This logic should be tidied up, preferably deprecating the use of cmp_to_key. Proposed work:

• Use Pytest to create functional tests at the level of calling list_.sort(key=cmp_to_key(sort_func))
• Change the sort functions to key functions, if possible.

[sadielbartholomew]

During the conversion from python2 to 3 @wxtim has used...

Oh that @wxtim! :smile: