ENH: Put information about fasta download files in file name/header

[corneliusroemer]

When I download fastas through covSpectrum/LAPIS, the file names are always identical, so I now have a hundred sequences (39).fasta lying around my download folder.

It would be much nicer if information about the query was contained in the fasta somewhere. In the file name, and maybe the exact URL that downloaded it in the fasta header (if there is such a thing!).