[LyX/master] Add support for the Elsevier CAS classes

[Juergen Spitzmueller]

commit 0ed40a012ac8901ef3fd1e8b5556f46d5e5aaa96
Author: Juergen Spitzmueller <spitz at lyx.org>
Date:   Sat Jul 4 08:44:13 2026 +0200

    Add support for the Elsevier CAS classes
    
    Provided by Marco Morandini, with tweaks by myself

 lib/Makefile.am                                    |    5 +
 .../Articles/Elsevier_CAS_%28Double_Column%29.lyx  | 1605 ++++++++++++++++++++
 .../Articles/Elsevier_CAS_%28Single_Column%29.lyx  | 1587 +++++++++++++++++++
 lib/layouts/cas-common.inc                         |  826 ++++++++++
 lib/layouts/cas-dc.layout                          |   35 +
 lib/layouts/cas-sc.layout                          |   31 +
 6 files changed, 4089 insertions(+)