dnf-plugin: implement disable, some fixes

* Enable logger
* automatically find needed chroot
* use _copr_ prefix for coprs .repo
* implement disable command
* if empty answer - use 'No'
* some fixes

Signed-off-by: Igor Gnatenko <i.gnatenko.brain@gmail.com>
dnf-plugin: implement list function

Signed-off-by: Igor Gnatenko <i.gnatenko.brain@gmail.com>