cli: Don't spam when downloading build
copr-cli download build uses wget without any verbosity control, which
generates roughly 10 lines per file. --no-verbose should suppress most
of the verbosity while still reporting basics and errors.
For example, my simple build 1128860 of single noarch rpm on 7 chroots,
it will generate 1834 lines. (In my simple build pipeline, this means
that the download just takes over the whole build log.) I've tested the
option (injecting wget wrapper in path) on Fedora 30 and in my case the
number of lines went down from 1834 to 182.