Implement `--quiet` option for cogctl

[christophermaier]

From @christophermaier on June 17, 2016 17:55

In order to more easily make command pipelines with cogctl, provide a --quiet/-q option on listing commands, which would simply return a list of the canonical identifiers for a thing.

As an example, right now you need to type something like this to assign all the permissions from a given bundle to a role:

cogctl permissions | grep $MY_BUNDLE | awk '{print $1 ":" $2}' | xargs cogctl permissions grant --role $MY_ROLE

With a --quiet / -q option, that could be reduced to:

cogctl permissions -q | grep $MY_BUNDLE | xargs cogctl permissions grant --role $MY_ROLE

assuming that cogctl permissions -q returned output like:

bundle1:perm1
bundle1:perm2
bundle2:perm1

Copied from original issue: operable/cog#779