* Refactor interface to PdmObjectHandle and PdmFieldHandle
Return objects instead of passing in structures as parameters
* Add nodiscard to several functions
* Remove redundant this->
* Rename to ptrReferencedObjectsByType
- Set default frequency enum to relative frequency [%]
- Set current view selected in filter by 3D view visibility by default
- Add labels for statistics data
- Add UI to change number of bins in histogram
- Add control of font size of axis values and axis titles