Set generic_user suffix from the config

Change-Id: I3d81c49a73094cf96ca6f8ada92b9044d7843ce3
UI basics to manage generic users

Change-Id: I103bdfdd564a4f242038e226cb6d2d552ebf4da9
Merge remote-tracking branch 'gerrit/3823_configure_generic_user' into HEAD

* gerrit/3823_configure_generic_user:
  UI basics to manage generic users
  Set generic_user suffix from the config

Change-Id: I75a41405b215144f25369bf9b621b9998b6df17d
This is Tuleap 6.2.99.29

Change-Id: I72d3f4c8c610c9099b8727f2a34ad112d31e4eb1