Standardize matcher headers to use .hpp suffix

tests/SelfTest/UsageTests/Compilation.tests.cpp

@@ -29,7 +29,7 @@ std::ostream& operator<<(std::ostream& out, foo::helper_1403 const&) {
 ///////////////////////////////
 
 #include <catch2/catch_test_macros.hpp>
-#include <catch2/matchers/catch_matchers_string.h>
+#include <catch2/matchers/catch_matchers_string.hpp>
 
 #include <cstring>
 

tests/SelfTest/UsageTests/Exception.tests.cpp

@@ -4,7 +4,7 @@
  */
 
 #include <catch2/catch_test_macros.hpp>
-#include <catch2/matchers/catch_matchers_string.h>
+#include <catch2/matchers/catch_matchers_string.hpp>
 
 #include <string>
 #include <stdexcept>

tests/SelfTest/UsageTests/Matchers.tests.cpp

@@ -5,10 +5,10 @@
 
 #include <catch2/catch_test_macros.hpp>
 #include <catch2/matchers/catch_matchers_exception.hpp>
-#include <catch2/matchers/catch_matchers_floating.h>
+#include <catch2/matchers/catch_matchers_floating.hpp>
 #include <catch2/matchers/catch_matchers_generic.hpp>
-#include <catch2/matchers/catch_matchers_string.h>
-#include <catch2/matchers/catch_matchers_vector.h>
+#include <catch2/matchers/catch_matchers_string.hpp>
+#include <catch2/matchers/catch_matchers_vector.hpp>
 #include <catch2/matchers/catch_matchers_templates.hpp>
 
 #include <algorithm>