In the users tab of the project details view, the users
table displays now the users which have a role on the project
through a group. ie: if a group is member of the project, and
if a user is a member of this group, then it will be displayed
in the table even if it is not directly a member of the project.
An extra column is added to the table: "role from group" which
display the list of "role(group)" the user has on the project.
To be able to test the membership of user to a project through
a group, "user_group_membership" data has been added to keystone
data.
Change-Id: I968bad7d285acfaf7a8ccd7458593bbcad498ce2
Partial-Bug: #1785263
6e754e5dad