Adds the endpoints

    /(groups|projects)/:id/members/all/:user_id

for finding individual members, including inherited membership,
complementing the existing endpoints

    /(groups|projects)/:id/members
    /(groups|projects)/:id/members/all
    /(groups|projects)/:id/members/:user_id

which list direct members, list all members (including inherited), and
find individual direct members, respectively.