“When a human rights or asylum claim has been refused or withdrawn… the decision maker will consider any further submissions and, if rejected, will then determine if they amount to a fresh claim. The submissions will amount to a fresh claim if they are significantly different from the material that has previously been considered. The submissions will only be significantly different if the content: (i) had not already been considered; and (ii) taken together with the previously considered material, created a realistic prospect of success, notwithstanding its rejection.”