functools.cached_property should support partial functions and partialmethod's

This way one can create cached_property's dynamically.

issue38524 is related.

Note that it is already possible, though awkward, to create cached properties dynamically. Using the example from PR GH-16838:

class ProcNet:
    pass

for proto in ('icmp', 'icmp6', 'raw', 'raw6', 'tcp', 'tcp6', 'udp', 'udp6', 'udplite', 'udplite6'):
    @cached_property
    def prop(self, *, proto=proto):
        with open(os.path.join("/proc/net", proto)) as file:
            return file.read()
    setattr(ProcNet, proto, prop)
    prop.__set_name__(ProcNet, proto)

IMO this is good enough, considering that this is all pretty much required for dynamically creating normal (uncached) properties and other types of descriptors.

According to issue38524, this should be closed.