`pyrefly report`: property setters/getters/deleters are counted separately

[jorenham]

If a property has a getter and a setter, it's still one property. But pyrefly report (0.60.1) would currently count that as 2 properties.

Also, the typables are counted as follows in typestats:

• a getter has 1 typable (the output)
• a setter has 1 typable (the input), because the None return type is trivial
• a deleter has no typables; the None return is trivial (so deleters can effectively be ignored)

So I propose that pyrefly report also implements it this way.