Support cached properties

[rixx]

No description provided.

[ghickman]

@rixx – could you rebase this over main to get the CI fix please?

[rixx]

@ghickman done, but with the other PR reverted, cached properties now land in both methods and properties, as this was leaning on the callable check more than I realised (would have put it in the same PR). Do you want me to add and not is_cached_property(member) to is_method, or do you want another overall approach?

[rixx]

I'm pushing a change to tests that checks that attributes are not present multiple times in the classify output. This will turn the test suite red so this PR does not get accidentally merged while it's in this state.

Looking at classify() some more, might me more worth it to iterate over members once and figure out what each should be, because including this PR, classify is up to six versions of [m for m in members if …].