Implementation of opt-out from catalog data during token validation.

The additional query parameter nocatalog in GET /v3/auth/tokens allows
the requestor to receive a token response omitting the catalog data.
This makes the token response sensibly smaller in case the catalog is
large due to the vaste deployment environment and available services.

e.g. GET /v3/auth/tokens?nocatalog

blueprint token-valid-catalog-opt-out

Change-Id: I272b1282acc0f04565d88c51b87dc7e30b141b7c
Merge "Implementation of opt-out from catalog data during token validation."