Add project to unscoped stack list response

For an unscoped stack list, stacks will possibly belong to several
different projects.  As a user who can see all stacks, it is useful to
be able to distinguish which stacks belong to which projects.

Co-Authored-By: Anderson Mesquita <andersonvom@gmail.com>
Change-Id: I4148a298ef7a41b815b477c49ff4aaf331845129
Implements: blueprint management-api
Merge "Add project to unscoped stack list response"