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/Services/TelnetServer/Client.cpp

@@ -170,10 +170,10 @@ ErrorOr<void> Client::send_data(StringView data)
 
         switch (c) {
         case '\n':
-            builder.append("\r\n");
+            builder.append("\r\n"sv);
             break;
         case IAC:
-            builder.append("\xff\xff");
+            builder.append("\xff\xff"sv);
             break;
         default:
             builder.append(c);