externals: Add catch2 v3.2.1

Merge commit '6879e5bb1c' as 'externals/catch'

externals/catch/tests/ExtraTests/X34-DuplicatedTestCaseMethodsDifferentFixtures.cpp

@@ -0,0 +1,27 @@
+
+//              Copyright Catch2 Authors
+// Distributed under the Boost Software License, Version 1.0.
+//   (See accompanying file LICENSE.txt or copy at
+//        https://www.boost.org/LICENSE_1_0.txt)
+
+// SPDX-License-Identifier: BSL-1.0
+
+/**\file
+ * Checks that test case methods with different class, but same name and
+ * tags name and tags are not reported as error.
+ */
+
+#include <catch2/catch_test_macros.hpp>
+
+class TestCaseFixture1 {
+public:
+    int m_a;
+};
+
+class TestCaseFixture2 {
+public:
+    int m_a;
+};
+
+TEST_CASE_METHOD(TestCaseFixture1, "A test case with duplicated name and tags", "[tag1]") {}
+TEST_CASE_METHOD(TestCaseFixture2, "A test case with duplicated name and tags", "[tag1]") {}