moved provider selection popup menu to be at the top of the main window

for now, i just removed the label that was in its place. i never found the label status to be very useful anyway.
I think that we are pushing forward to that approach of having a simple UI and separated logic (idk if exactly MVC but similar).
We moved all the logic that we could to the backend (no qt stuff) and we do the requests using zmq and triggering qt signals as result.
There was a really big refactor but still we have lots of work to do.

> For me, the thing that is really unclear is how you could create a model that doesn't have Qt code but that could still interface with Qt signals and slots. 

Well, I usually do something like this:
```python
def on_some_button_clicked(self):
    a = some_lib.do_some_action()  # <- does not know about qt
    self.some_signal.emit(a)
```

So, in `some_lib` you have all your logic, no qt involved.
But maybe you're talking about doing things the other way around, like the logic driving the UI changes instead of UI using specific logic from a lib.