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/rendercontext.h

@@ -0,0 +1,72 @@
+/*
+  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_RENDERCONTEXT_H
+#define KTEXTTEMPLATE_RENDERCONTEXT_H
+
+#include "ktexttemplate_export.h"
+
+#include <QVariantHash>
+
+/// @headerfile rendercontext.h <KTextTemplate/RenderContext>
+
+namespace KTextTemplate
+{
+
+class ContextPrivate;
+class TemplateImpl;
+class Node;
+
+class RenderContextPrivate;
+
+/**
+   @brief Provides storage facility for state while rendering a template.
+
+   This class can not be instatiated by users of it. An instance
+   of **%RenderContext** is available through Context::renderContext() for use
+   with implementations of re-entrant template tags.
+ */
+class KTEXTTEMPLATE_EXPORT RenderContext
+{
+public:
+    /**
+      Returns the data for the node @p scopeNode.
+     */
+    QVariant &data(const Node *const scopeNode);
+
+    /**
+      Returns whether the **%RenderContext** contains data for @p scopeNode.
+     */
+    bool contains(Node *const scopeNode) const;
+
+    /**
+      Destructor
+     */
+    ~RenderContext();
+
+#ifndef K_DOXYGEN
+private:
+    RenderContext();
+
+    void push();
+
+    void pop();
+
+private:
+    friend class ContextPrivate;
+    friend class TemplateImpl;
+
+    Q_DISABLE_COPY(RenderContext)
+    Q_DECLARE_PRIVATE(RenderContext)
+    RenderContextPrivate *const d_ptr;
+#endif
+};
+}
+
+#endif