Add StringMaker for std::(w)string_view

Fixes #1375

projects/SelfTest/UsageTests/ToStringGeneral.tests.cpp

@@ -116,6 +116,18 @@ TEST_CASE("Static arrays are convertible to string", "[toString]") {
     }
 }
 
+#ifdef CATCH_CONFIG_CPP17_STRING_VIEW
+
+TEST_CASE("String views are stringified like other strings", "[toString][approvals]") {
+    std::string_view view{"abc"};
+    CHECK(Catch::Detail::stringify(view) == R"("abc")");
+
+    std::string_view arr[] { view };
+    CHECK(Catch::Detail::stringify(arr) == R"({ "abc" })");
+}
+
+#endif
+
 namespace {
 
 struct WhatException : std::exception {