#14739 Fix null pointer crash in intersection result text builders

Guard against a null flatIntersectionPartMgr() in RiuResultTextBuilder and RiuFemResultTextBuilder. The part manager is only created when the display model is built, but result text can be requested (via selection updates) before that happens, e.g. right after appending a new intersection.

ApplicationLibCode/UserInterface/RiuFemResultTextBuilder.cpp

@@ -151,7 +151,7 @@ QString RiuFemResultTextBuilder::geometrySelectionText( QString itemSeparator )
                 text += QString( ", ijk[%1, %2, %3]" ).arg( i ).arg( j ).arg( k ) + itemSeparator;
 
                 QString formattedText;
-                if ( m_2dIntersectionView )
+                if ( m_2dIntersectionView && m_2dIntersectionView->flatIntersectionPartMgr() )
                 {
                     formattedText = QString( "Horizontal length from well start: %1" ).arg( m_intersectionPointInDisplay.x(), 5, 'f', 2 );
                     text += formattedText + itemSeparator;

ApplicationLibCode/UserInterface/RiuResultTextBuilder.cpp

@@ -249,7 +249,7 @@ QString RiuResultTextBuilder::geometrySelectionText( const QString& itemSeparato
             if ( m_intersectionPointInDisplay != cvf::Vec3d::UNDEFINED )
             {
                 QString formattedText;
-                if ( m_2dIntersectionView )
+                if ( m_2dIntersectionView && m_2dIntersectionView->flatIntersectionPartMgr() )
                 {
                     formattedText = QString( "Horizontal length from well start: %1" ).arg( m_intersectionPointInDisplay.x(), 5, 'f', 2 );
                     text += formattedText + itemSeparator;