[MaL] Added output formatter for Eigen dense types

MathLib/FormattingUtils.h

+/**
+ * \file
+ * \copyright
+ * Copyright (c) 2012-2023, OpenGeoSys Community (http://www.opengeosys.org)
+ *            Distributed under a Modified BSD License.
+ *              See accompanying file LICENSE.txt or
+ *              http://www.opengeosys.org/project/license
+ *
+ */
+
+#pragma once
+
+#include <fmt/ostream.h>
+
+#include <Eigen/Core>
+#include <concepts>
+
+template <typename T>
+requires std::derived_from<T, Eigen::DenseBase<T>>
+struct fmt::formatter<T> : fmt::ostream_formatter
+{
+};