Add debian/apertis/copyright

Signed-off-by: Dylan Aïssi <dylan.aissi@collabora.com>

debian/apertis/copyright

+Format: https://www.debian.org/doc/packaging-manuals/copyright-format/1.0/
+
+Files: debian/*
+Copyright: no-info-found
+License: BSD-4-clause
+
+Files: dialects/freebsd/include/*
+Copyright: 1993, Paul Kranenburg
+License: BSD-4-clause
+
+Files: dialects/osr/include/*
+Copyright: 1980, 1983, 1988, Regents of the University of California.
+License: BSD-4-clause-UC
+
+Files: dialects/osr/include/sys/*
+Copyright: 1991, 1993, The Regents of the University of California.
+License: BSD-4-clause-UC
+
+Files: scripts/sort_res.perl5
+Copyright: 2004-2005, - Fabian Frederick <fabian.frederick@gmx.fr>
+License: GPL-2+
+
+Files: * 00FAQ NEW/* NEW/ckssh.gz NEW/cktn.gz NEW/irix.zip NEW/lsofAPI.tar.gz NEW/posting.gz NEW/pstat.proto.gz NEW/rns.c.gz NEW/usage.c dialects/darwin/* dialects/darwin/kmem/* support/*
+Copyright: Purdue Research Foundation, West Lafayette, Indiana 47907 2002 - 2011
+License: Purdue
+
+Files: dialects/darwin/libproc/dfile.c dialects/darwin/libproc/dlsof.h dialects/darwin/libproc/dproc.c dialects/darwin/libproc/dfile.c dialects/darwin/libproc/dlsof.h dialects/darwin/libproc/dproc.c dialects/darwin/libproc/dfile.c dialects/darwin/libproc/dlsof.h dialects/darwin/libproc/dproc.c
+Copyright: 2005-2007, Apple Computer, Inc.  All rights reserved.
+License: Purdue

debian/apertis/copyright.whitelist

+# BSD-4-clause code only used for FreeBSD, do not affect the licensing of the artifacts
+dialects/freebsd/include/*
+# Debian metadata BSD-4-clause
+debian/**

debian/apertis/copyright.yml

+dialects/osr/include/netdb.h:
+  override-license: BSD-4-clause-UC
+dialects/osr/include/sys/cdefs.h:
+  override-license: BSD-4-clause-UC