fix: log cache hits distinct from fetch

[mbtools]

Avoid confusion between actual remote fetches and cache hits (which don't involve a fetch).

Ref npm/pacote#403 (comment)

[wraithgar]

After sitting on this for awhile I think this is the right choice. The http loglevel indicates that at the highest level, the code is trying to get something via an http url. The logging verb then informs the end user what mechanism was actually used to retrieve the data (cache vs fetch).