Skip distance check when clicking in the plot, always select closest curve
When pressing CTRL, toggle highlighted curves
Allow multi select of realizations in Project Tree
Avoid curve highlight operation during zoom
Make sure wheel zoom works for a single plot
* 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
* Make curve selection optional to avoid flickering in depth plots
* Replace undefined with zero for some curves
* Add spacing factor for min and max depth