Add waiters to OSC Manila commands for OpenStack Shared File Systems Service (Manila)

Add an option for commands to return only after the action has been performed. Add a '--wait' argument to all OSC commands except the ones for 'list' and 'show'.

Manila support in python-openstackclient for OpenStack Shared File Systems Service (Manila)

python-openstackclient is the default command line client for many OpenStack projects. And it has been discussed that in Train it will be a community goal to have support in it. So all projects that currently don't have full support, should migrate. The intent of this spec is to identify the commands to be implemen...