Merge branch 'DataExplorerFixWarnings' into 'master'

DataExplorer: fix Qt deprecated warnings

See merge request ogs/ogs!3643

Applications/DataExplorer/Base/TreeModel.cpp

@@ -176,7 +176,7 @@ Qt::ItemFlags TreeModel::flags(const QModelIndex& index) const
 {
     if (!index.isValid())
     {
-        return nullptr;
+        return Qt::NoItemFlags;
     }
 
     return Qt::ItemIsEnabled | Qt::ItemIsSelectable;
@@ -254,7 +254,7 @@ void TreeModel::setupModelData(const QStringList& lines, TreeItem* parent)
         {
             // Read the column data from the rest of the line.
             QStringList columnStrings =
-                lineData.split("\t", QString::SkipEmptyParts);
+                lineData.split("\t", Qt::SkipEmptyParts);
             QList<QVariant> columnData;
             for (int column = 0; column < columnStrings.count(); ++column)
             {