fiGUI PushLabelWidth & PopLabelWidth not balanced - Memory leak & UI Issues

[gjroelofs]

fiGUI.PushLabelWidth() operates on an internal stack mechanism that gets pushed to by several occurences, but gets only sparsely Popped().

This leads to several issues:

• The prefix label's width can be wildly incorrect, based on a cached value that's incorrect. This mostly manifests itself through the actual component besides the prefix Label becoming smaller and/or vanishing entirely
• Expanding List & Stack that as Inspector drawing goes on hog memory.

Occurences:

• https://github.com/jacobdufault/fullinspector/blob/f567f2a0b2c477d3a794d9b03ccf571a3229b7c3/Assets/FullInspector2/Core/Editor/IBehaviorEditor.cs#L77
• https://github.com/jacobdufault/fullinspector/blob/f567f2a0b2c477d3a794d9b03ccf571a3229b7c3/Assets/FullInspector2/Core/Editor/IPropertyEditorExtensions.cs#L88