test/catch2: Use split headers and static library

This is required for compatability with Catch2 3.x

Change-Id: I53ecff8911345e8f037aee825b7abf30b90552d2
Signed-off-by: William A. Kennington III <wak@google.com>
diff --git a/test/raw.cpp b/test/raw.cpp
index b781054..79fb2ad 100644
--- a/test/raw.cpp
+++ b/test/raw.cpp
@@ -1,5 +1,9 @@
 #include <array>
+#if __has_include(<catch2/catch.hpp>)
 #include <catch2/catch.hpp>
+#else
+#include <catch2/catch_test_macros.hpp>
+#endif
 #include <endian.h>
 #include <stdexcept>
 #include <stdplus/raw.hpp>