Fix Qt6 deprecated APIs: QCheckBox::checkStateChanged, ExploratoryLocationViewshed

- Replace QCheckBox::stateChanged with checkStateChanged in:
  - lts_dialog.cpp
  - simple_esri_layer.cpp (2 occurrences)
  - layer_control_widget.cpp
  - symbol_dialog.cpp
- Replace LocationViewshed with ExploratoryLocationViewshed (ArcGIS SDK v300):
  - viewshed_analysis.h/.cpp
  - ViewshedLocation.h/.cpp
  - function_dialog.cpp (include)
- Update ViewshedLocation member variable type to ExploratoryLocationViewshed

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

qt6-after/qt6-migrated-legatus/external/include/KF6/KTextTemplate/ktexttemplate/outputstream.h

@@ -0,0 +1,134 @@
+/*
+  This file is part of the KTextTemplate library
+
+  SPDX-FileCopyrightText: 2010 Stephen Kelly <steveire@gmail.com>
+
+  SPDX-License-Identifier: LGPL-2.1-or-later
+
+*/
+
+#ifndef KTEXTTEMPLATE_OUTPUTSTREAM_H
+#define KTEXTTEMPLATE_OUTPUTSTREAM_H
+
+#include "ktexttemplate_export.h"
+
+#include <QSharedPointer>
+#include <QTextStream>
+
+namespace KTextTemplate
+{
+
+class SafeString;
+
+/// @headerfile outputstream.h <KTextTemplate/OutputStream>
+
+/**
+  @brief The **%OutputStream** class is used to render templates to a
+  QTextStream
+
+  A **%OutputStream** instance may be passed to the render method of a Template
+  to render the template to a stream.
+
+  @code
+    QFile outputFile("./output");
+    outputFile.open(QFile::WriteOnly);
+    QTextStream tstream( &outputFile );
+
+    OutputStream os(&tstream);
+    t->render( &os, &context );
+  @endcode
+
+  The **%OutputStream** is used to escape the content streamed to it. By
+  default, the escaping is html escaping, converting "&" to "&amp;" for example.
+  If generating non-html output, the @ref escape method may be overriden to
+  perform a different escaping, or non at all.
+
+  If overriding the @ref escape method, the @ref clone method must also be
+  overriden to return an **%OutputStream** with the same escaping behaviour.
+
+  @code
+    class NoEscapeStream : public KTextTemplate::OutputStream
+    {
+    public:
+      // ...
+
+      QString escape( const QString &input ) const
+      {
+        return input;
+      }
+
+      QSharedPointer<OutputStream> clone( QTextStream *stream ) const
+      {
+        return QSharedPointer<NoEscapeStream>::create( stream );
+      }
+    };
+  @endcode
+
+  @author Stephen Kelly <steveire@gmail.com>
+*/
+class KTEXTTEMPLATE_EXPORT OutputStream
+{
+public:
+    /**
+      Creates a null **%OutputStream**. Content streamed to
+      this **%OutputStream** is sent to <tt>/dev/null</tt>
+    */
+    OutputStream();
+
+    /**
+      Creates an **%OutputStream** which will stream content to @p stream
+      with appropriate escaping.
+    */
+    explicit OutputStream(QTextStream *stream);
+
+    /**
+      Destructor
+    */
+    virtual ~OutputStream();
+
+    /**
+      Returns an escaped version of @p input. Does not write anything to the
+      stream.
+    */
+    virtual QString escape(const QString &input) const;
+
+    /**
+      Returns an escaped version of @p input. Does not write anything to the
+      stream.
+    */
+    QString escape(const SafeString &input) const;
+
+    /**
+      Returns a cloned **%OutputStream** with the same filtering behaviour.
+    */
+    virtual QSharedPointer<OutputStream> clone(QTextStream *stream) const;
+
+    /**
+      Returns @p after escaping it, unless @p input is "safe", in which case,
+      @p input is returned unmodified.
+    */
+    QString conditionalEscape(const KTextTemplate::SafeString &input) const;
+
+    /**
+      Writes @p input to the stream after escaping it.
+    */
+    OutputStream &operator<<(const QString &input);
+
+    /**
+      Writes @p input to the stream after escaping it if necessary.
+    */
+    OutputStream &operator<<(const SafeString &input);
+
+    /**
+      Reads the content of @p stream and writes it unmodified to the result
+      stream.
+    */
+    OutputStream &operator<<(QTextStream *stream);
+
+private:
+    QTextStream *m_stream;
+    Q_DISABLE_COPY(OutputStream)
+};
+}
+
+#endif