C++: Accept changes to getValueText

cpp/ql/test/library-tests/constants/constants/strings.expected

@@ -1,6 +1,6 @@
-| Narrow \u00a2 One | "Narrow \\xa2 One" |
-| Narrow \u00a2 Two | "Narrow \\xa2 Two" |
+| Narrow \u00a2 One | Narrow \u00a2 One |
+| Narrow \u00a2 Two | Narrow \u00a2 Two |
 | Narrow \u00a2 Zero | "Narrow \\xa2 Zero" |
-| Wide \u20ac One | Widen1("Wide \\x20ac One" |
-| Wide \u20ac Two | Widen2("Wide \\x20ac Two" |
+| Wide \u20ac One | Wide \u20ac One |
+| Wide \u20ac Two | Wide \u20ac Two |
 | Wide \u20ac Zero | L"Wide \\x20ac Zero" |