Add warnings for Batch Transfers

[rkalis]

Seaport and other platforms allow "batch transfers" of NFTs and other assets. This is a potentially harmful action that we should warn on. We should probably create a new class of warnings "Batch Transfers" that checks whether these kinds of signatures or transactions are sent.

We should also investigate which big platforms exist that have this functionality besides Seaport.

[mabsattar]

Hi @rkalis I'd like to work on this, can you please assign me?