Update service catalog to contain a non-project ID cinder endpoint

[Lance Bragstad]

Right now cinder is typically deployed with a project ID template for each cinder endpoint.

Keystone templates the URL with the project ID of the project-scoped token in the service catalog. This endpoint won't populate in service catalogs for system-scoped tokens. To fix this, we can add an endpoint without a templated project ID.

This will allow system users to have a cinder endpoint in their service catalog.

[Dr. Jens Harbott (j-harbott)]

a) I'd prefer to have different bug reports for devstack and tripleo, this mix is confusing. Can we use this one for devstack only?
b) Is the new endpoint setup documented somewhere? https://docs.openstack.org/cinder/latest/install/cinder-controller-install-ubuntu.html#install-and-configure-components still shows the templated endpoint, too.