Node width too large for custom widgets

[FlorianRaichle]

Thank you for this amazing project! I have noticed a sizing issue when embedding custom widgets:

Nodes with a custom widget become too wide based on their name.

The issue seems to be that the custom widget width is just added to the total width. Instead it should probably go into the calculation together with the port text width. https://github.com/jchanvfx/NodeGraphQt/blob/deaf3b1ec86dad5705bbd973d273356420eaa99c/NodeGraphQt/qgraphics/node_base.py#L394

This is based on this example using 0.6.35.