Use cafPdmUiButton instead of bool in PdmField

* Adopts dynamic PDM buttons with lambda callbacks

Refactors PDM push buttons from boolean fields to use the `addNewButton` API with direct lambda callbacks.

This change enforces a new coding guideline to extract complex or multi-line lambdas to dedicated `on*Clicked()` methods, improving code readability and maintainability.

- Replaces `PdmField` button fields with `PdmUiOrdering::addNewButton` calls.
- Extracts multi-line/control-flow lambdas into named methods in `RimFlowCharacteristicsPlot`, `RimGeoMechCase`, and `RimStatisticsContourMap`.
- Removes obsolete `defineEditorAttribute` overrides and `fieldChangedByUi` logic for these buttons.
- Updates `RimWellPathFracture` to utilize base class-provided button creation.
- Adds new lambda line-count guideline to the coding style documentation.
- Includes minor build fixes, such as adding `cafPdmUiButton.h` and correcting tooltip API usage.

ApplicationLibCode/ProjectDataModel/ContourMap/RimStatisticsContourMap.h

@@ -101,6 +101,7 @@ protected:
 
 private:
     void computeStatistics();
+    void onComputeStatisticsClicked();
     void doStatisticsCalculation( std::map<size_t, std::vector<std::vector<double>>>& timestep_results );
 
     RimFormationNames*           activeFormationNames() const;
@@ -113,7 +114,6 @@ private:
     caf::PdmField<RimContourMapProjection::ResultAggregation> m_resultAggregation;
     caf::PdmField<std::vector<int>>                           m_selectedTimeSteps;
     caf::PdmChildField<RimEclipseResultDefinition*>           m_resultDefinition;
-    caf::PdmField<bool>                                       m_computeStatisticsButton;
     caf::PdmField<bool>                                       m_enableFormationFilter;
     caf::PdmField<std::vector<QString>>                       m_selectedFormations;
     caf::PdmPtrField<RimEclipseCase*>                         m_primaryCase;