bittorrent downloader: using inversed log levels, need align

[AskAlexSharov]

now erigon-lib/downloader/downloadercfg/downloadercfg.go:New using github.com/anacrolix/log.Level which matching to --torrent.verbosity flag.
But it's values are inversed to our logger levels.
Need somehow align this values - for example make --torrent.verbosity flag to follow our levels ( to match with --log.console.verbosity) and then convert.

By default:

• embedded Downloader must print not much logs - only high-level things (download rates, etc...). And print more details in lvl.Debug.
• external Downloader must print more details by default (have 1 verbosity level higher)

[anacrolix]

Is this still a thing? I can take a look while working on upstream compatibility.

[AskAlexSharov]

yes