Bug 28386: Add the 3 unknown authors back into the contributors list with a note

Bug 28386: Add the 3 unknown authors back into the contributors list with a note

Signed-off-by: Jonathan Druart <jonathan.druart@bugs.koha-community.org>
(cherry picked from commit 9f8abe3618a054238910cbdbf2ffdf1416b8a03b)
Signed-off-by: Fridolin Somers <fridolin.somers@biblibre.com>
(cherry picked from commit 60d0fa95e081a58c594f2c3850769c0016dd6245)
Signed-off-by: Victor Grousset/tuxayo <victor@tuxayo.net>
(cherry picked from commit bb34ad6893a6821bb0db1d0456f8d96b1043e7be)
Signed-off-by: Wainui Witika-Park <wainuiwitikapark@catalyst.net.nz>
(cherry picked from commit bb34ad6893a6821bb0db1d0456f8d96b1043e7be)