Memory leaks when resizing 2D views

A lot of (2D) views have leaks when being resized. Compiling with VTK_DEBUG_LEAKS=ON detects no leaks at the end of the execution.

Tested on master

Leaking :

• Box chart
• Bar chart
• Histogram
• Line chart
• Parallel coordinates
• Python charts
• Point chart
• Quartile chart

Not leaking :

• Render view
• Spreadsheet view

Step to reproduce

• Open paraview and any of the views mentioned earlier.
• Resize by dragging the limit between the layout and the pipeline browser.

Loading / displaying data is not mandatory. It doesn't matter if the view is a new layout or not.