Tools: show functions returning QWidget

[antirotor]

Changelog Description

Make all show_*() functions to return QWidget so the code calling it can work with it. Also add some type annotations and docstrings.

Additional info

This is needed for example in Unreal, where you need to call unreal.parent_external_window_to_slate() on winId() of the widget. Might be useful for other things too.

Tip

For PR that can make use of it, see ynput/ayon-unreal#269

Testing notes:

Without proper support this cannot be easily tested. However, all should work as before.

[iLLiCiTiT]

Code changes look ok, can't verify them.

I would personally NOT do it, and rather force Unreal to use get_* methods to handle that.

[BigRoy]

Nice. I agree with essentially all of @iLLiCiTiT 's suggestions here - so after that looks good to me.

[antirotor]

I would personally NOT do it, and rather force Unreal to use get_* methods to handle that.

but then you would basically need to reimplement all show_*() in unreal and perhaps elsewhere.

applied suggestions.

[iLLiCiTiT]

but then you would basically need to reimplement all show_*() in unreal and perhaps elsewhere.

Yeah, you kinda had to reimplement everything here instead...