#8611 QtChart : Improve time axis grid intervals

Use QCatetoryAxis to display date labels
Use Qwt label formatting and scale dividing tools to produce text labels

ApplicationLibCode/UserInterface/RiuQwtDateScaleWrapper.h

@@ -0,0 +1,45 @@
+/////////////////////////////////////////////////////////////////////////////////
+//
+//  Copyright (C) 2022     Equinor ASA
+//
+//  ResInsight is free software: you can redistribute it and/or modify
+//  it under the terms of the GNU General Public License as published by
+//  the Free Software Foundation, either version 3 of the License, or
+//  (at your option) any later version.
+//
+//  ResInsight is distributed in the hope that it will be useful, but WITHOUT ANY
+//  WARRANTY; without even the implied warranty of MERCHANTABILITY or
+//  FITNESS FOR A PARTICULAR PURPOSE.
+//
+//  See the GNU General Public License at <http://www.gnu.org/licenses/gpl.html>
+//  for more details.
+//
+/////////////////////////////////////////////////////////////////////////////////
+#pragma once
+
+#include "RiaQDateTimeTools.h"
+
+#include <qwt_date_scale_draw.h>
+#include <qwt_date_scale_engine.h>
+
+class RiuQwtDateScaleWrapper
+{
+public:
+    RiuQwtDateScaleWrapper();
+
+    void setFormatStrings( const QString&                          dateFormat,
+                           const QString&                          timeFormat,
+                           RiaQDateTimeTools::DateFormatComponents dateComponents,
+                           RiaQDateTimeTools::TimeFormatComponents timeComponents );
+
+    void    setMaxMajorTicks( int tickCount );
+    QString formatStringForRange( const QDateTime& min, const QDateTime& max );
+
+    std::tuple<double, double, int>         adjustedRange( const double& min, const double& max ) const;
+    std::vector<std::pair<double, QString>> positionsAndLabels( const double& min, const double& max );
+
+private:
+    QwtDateScaleDraw   m_scaleDraw;
+    QwtDateScaleEngine m_scaleEngine;
+    int                m_maxMajorTicks;
+};