The network error on accessing to the remote blast database should be human-readable

Scenario to reproduce:

1. Search something in a local BLAST database. There should be results.
2. Call context menu on the result annotation and fetch sequences from the remote database.
   Expected state: there is an error.

The error message is:

Task

Unknown macro: {Load remote document and open view}

finished with error: Cannot find BL_ORD_ID in NCBI GenBank (DNA sequence) database: NetworkReply error 299

NetworkReply should be human-readable, it can be easily converted to a string. Also, it is a well-known error (the blast result is not found in the database) so the error message can be a bit more clear.