Remove sorting in the extract_attributes

In default, prmd renders sorted attributes by using `extract_attributes` helper method, but the behavior is inconsistent with `schema_value_example`'s one.

The inconsistent is started since 33a653bccbce9c2f4b1df4aa186cd3cd16a13a39. `schema_value_example` renders no-sorted attributes by the chages, but `extract_attributes` didn't.

I think `extract_attributes` should not sort properties too for the same reason of 33a653bccbce9c2f4b1df4aa186cd3cd16a13a39 changes.