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/Utilities/userdel.cpp

@@ -51,7 +51,7 @@ ErrorOr<int> serenity_main(Main::Arguments arguments)
     auto& target_account = account_or_error.value();
 
     if (remove_home) {
-        TRY(Core::System::unveil(target_account.home_directory().characters(), "c"));
+        TRY(Core::System::unveil(target_account.home_directory(), "c"sv));
     } else {
         TRY(Core::System::pledge("stdio wpath rpath cpath fattr"));
     }