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/LibWeb/HTML/Parser/HTMLEncodingDetection.cpp

@@ -42,7 +42,7 @@ Optional<StringView> extract_character_encoding_from_meta_element(String const&
     GenericLexer lexer(lowercase_string);
 
     for (;;) {
-        auto charset_index = lexer.remaining().find("charset");
+        auto charset_index = lexer.remaining().find("charset"sv);
         if (!charset_index.has_value())
             return {};