And adopt argument passing tests as well.

turns out that `C.staticmethod.__func__` doesn't actually work :O

The selected edges is covered by `NormalDataflowTest.ql` now... and
reading the test-output changes in `edges` is just going to make commits
larger while not providing any real value.

I don't see the value from this, so just going to outright delete it.
(it actually stayed alive for quite some time in the original git history,
but never seemed to be that useful.)

We never had a showcase of how keyword arguments were handled

This adds inline expectations, next commit will remove old annotations
code... but I thought it would be easier to review like this.

I ported the predicates showing difference between points-to and
type-tracking, since it's helpful to see the list of differences,
instead of having to parse expectations!

No longer needed since we're using an established testing framework now

to the new call-graph test setup. Nice that we can write `MISSING:` now!