* 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
* #9277 Observed Data : Assign case ID when importing observed data
If no case ID is assigned, the first observed case is always used when creating new plots of observed data
* #9278 Match on summary vector name when curve unit text is missing
* Make sure the subplot selected in the tree is shown in the multiplot viewer.
* Clean up multiplot toolbar handling a bit
* Remove old summary plot toolbar.