Support numeric aware sorting on Windows and macOS

* Fix #8356 - Qt does not enable numeric aware sorting when using locale sort. Extracted both Windows and macOS locale aware sorting code and added the appropriate numeric aware flag.

Note: There is no std library way to do this so Linux is out of luck for now.

src/gui/SortFilterHideProxyModel.cpp

@@ -16,6 +16,7 @@
  */
 
 #include "SortFilterHideProxyModel.h"
+#include <QCollator>
 
 SortFilterHideProxyModel::SortFilterHideProxyModel(QObject* parent)
     : QSortFilterProxyModel(parent)
@@ -41,3 +42,16 @@ bool SortFilterHideProxyModel::filterAcceptsColumn(int sourceColumn, const QMode
 
     return sourceColumn >= m_hiddenColumns.size() || !m_hiddenColumns.at(sourceColumn);
 }
+
+bool SortFilterHideProxyModel::lessThan(const QModelIndex& left, const QModelIndex& right) const
+{
+    auto leftData = sourceModel()->data(left, sortRole());
+    auto rightData = sourceModel()->data(right, sortRole());
+    if (leftData.type() == QVariant::String) {
+        QCollator sorter;
+        sorter.setNumericMode(true);
+        return sorter.compare(leftData.toString(), rightData.toString()) < 0;
+    }
+
+    return QSortFilterProxyModel::lessThan(left, right);
+}

src/gui/SortFilterHideProxyModel.h

@@ -32,6 +32,7 @@ public:
 
 protected:
     bool filterAcceptsColumn(int sourceColumn, const QModelIndex& sourceParent) const override;
+    bool lessThan(const QModelIndex& left, const QModelIndex& right) const override;
 
 private:
     QBitArray m_hiddenColumns;