Everywhere: Add sv suffix to strings relying on StringView(char const*)

Each of these strings would previously rely on StringView's char const*
constructor overload, which would call __builtin_strlen on the string.
Since we now have operator ""sv, we can replace these with much simpler
versions. This opens the door to being able to remove
StringView(char const*).

No functional changes.

Userland/Libraries/LibJS/Lexer.h

@@ -16,7 +16,7 @@ namespace JS {
 
 class Lexer {
 public:
-    explicit Lexer(StringView source, StringView filename = "(unknown)", size_t line_number = 1, size_t line_column = 0);
+    explicit Lexer(StringView source, StringView filename = "(unknown)"sv, size_t line_number = 1, size_t line_column = 0);
 
     Token next();