Add worker for BLAST results filtering

There's a request from a user in our vk public page. Say, we have a bunch of sequences. It's needed to do a BLAST request for each of them, then pick those which have highest BLAST scores and create some report containing selected sequences along with their BLAST scores, query coverage and identity. A new worker should be added to WD that is able to accumulate BLAST results and form the report afterwards.

See the attached file as the example of input data.