Performance updates (#9082)

* Avoid creation of curve legend widgets during construction of a multi plot
* Make sure default z-value is correct to avoid expensive Qwt updates
* Avoid duplicate plot updates
* Do not create internal Qwt legend by default
* RFT import: Avoid expensive method throwing exception if no data is found

ApplicationLibCode/Commands/PlotBuilderCommands/RicAppendSummaryPlotsForObjectsFeature.cpp

@@ -95,12 +95,11 @@ void RicAppendSummaryPlotsForObjectsFeature::appendPlots( RimSummaryMultiPlot* s
                 summaryMultiPlot->addPlot( duplicatedPlot );
 
                 duplicatedPlot->resolveReferencesRecursively();
+                duplicatedPlot->loadDataAndUpdate();
             }
         }
         info.incrementProgress();
     }
-
-    summaryMultiPlot->loadDataAndUpdate();
 }
 
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