Split cliutils

Module cliutils should not have dependency to apiclient, so:
 - Exception apiclient.exceptions.MissingArgs is moved to cliutils
 - cliutils.find_resource is moved to new module apiclient.utils.

Change-Id: Ifee0cfd077b0cf53a47cbc9066990071d1e27292
Merge "Split cliutils"