Class TerminalStripLayoutPattern can be save/load from xml

Add a new class TerminalStripLayoutPatternXml used to
save / load a TerminalStripLayoutPattern class into a xml.

Also create the namespace QETSVG used to read/write some
svg element / attribute to xml. This class is used by the
class TerminalStripLayoutPatternXml.

sources/xml/terminalstriplayoutpatternxml.h

@@ -0,0 +1,41 @@
+/*
+    Copyright 2006-2025 The QElectroTech Team
+    This file is part of QElectroTech.
+
+    QElectroTech 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 2 of the License, or
+    (at your option) any later version.
+
+    QElectroTech 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 for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with QElectroTech.  If not, see <http://www.gnu.org/licenses/>.
+*/
+#ifndef TERMINALSTRIPLAYOUTPATTERNXML_H
+#define TERMINALSTRIPLAYOUTPATTERNXML_H
+
+#include <QDomElement>
+#include <QSharedPointer>
+
+class TerminalStripLayoutPattern;
+
+/**
+ * @brief The TerminalStripLayoutPatternXml class
+ * A class used to save/restor a @class TerminalStripLayoutPattern to
+ * xml
+ */
+class TerminalStripLayoutPatternXml
+{
+    public:
+        static QDomElement toXml(const QVector<QSharedPointer<TerminalStripLayoutPattern>> &patterns, QDomDocument &document);
+        static QVector<QSharedPointer<TerminalStripLayoutPattern>> fromXml(const QDomElement &element);
+
+        static QDomElement toXml (const QSharedPointer<TerminalStripLayoutPattern> &pattern, QDomDocument &document);
+        static void fromXml(QSharedPointer<TerminalStripLayoutPattern> &layout, const QDomElement &element);        
+};
+
+#endif // TERMINALSTRIPLAYOUTPATTERNXML_H