Implement AskUser dialog

[BigRoy]

Implementation

A draft implementation has been pushed just now for AskUserDialog. This is the fusionless class for Fusion's comp.AskUser. Consider it a draft implementation, so make sure to test the functionality once you start adopting it.

An example of usage is available here: https://github.com/BigRoy/fusionless/blob/master/examples/comp/ask_user_dialog.py

The resulting dialog:

As far as I tested all functionality should work.

Discussion

I'm not too fond of how Fusion returns some of the values from the dialog.

For example a position control returns the values as {1.0: 0.5, 2.0: 0.5, 3.0: 0.5}. So basically it is a dictionary with three values (even though the control shows only X, Y). Preferably I would have it return it as a list or tuple, like (0.5, 0.5, 0.5) (for X, Y, Z if the Z-component is shown in the UI which I haven't seen yet).

Furthermore I'm opening this issue to open up discussion about the overall implementation.

[LarsCawley]

This seems to work really well. I would like to suggest an optional argument for multibutton and dropdown controls to return the selected string value.

[BigRoy]

Where would you like to pass that optional argument? When adding the button?

Something like:

dialog.add_multibutton("id", result="str")

It feels a bit odd. Do you have a better idea maybe? I think I need my morning coffee
Or should it maybe just always return the string?