sip: make configure more verbose. print config status for every binding

[Milan Hauth]

make it easier to debug a failing build

example:

sipbuild/project.py

```py
    def update_buildable_bindings(self):
        # ...

        for b in list(self.bindings.values()):
            if b.is_buildable():
                print(f"Binding {b.name} will be built.")
            else:
                print(f"Binding {b.name} will not be built.")
                del self.bindings[b.name]
```