implement image tag into OSC

Add tag filtering options for listing images.

 openstack image list [-h] [-f {csv,json,table,value,yaml}] [-c COLUMN]
                            [--max-width <integer>] [--noindent]
                            [--quote {all,minimal,none,nonnumeric}]
                            [--public | --private | --shared]
                            [--property <key=value>] [--long]
                            [--sort <key>[:<direction>]] [--limit <limit>]
                            [--marker <marker>]
                            [--tag <TAG>]