LU-17347 debs: also move .ddeb files into debs/

LU-17347 debs: also move .ddeb files into debs/

When building debian packages, the resulting packages are
moved into a 'debs/' subdir.

Don't miss the debug symbol packages 'dbgsym', which are
suffixed .ddeb.

Also add .buildinfo file.

Test-Parameters: trivial
Change-Id: I52d0bddfaafc67c4a2a2dbc786d7f320c0b979f8
Signed-off-by: Aurelien Degremont <adegremont@nvidia.com>
Reviewed-on: https://review.whamcloud.com/c/fs/lustre-release/+/53378
Tested-by: jenkins <devops@whamcloud.com>
Tested-by: Maloo <maloo@whamcloud.com>
Reviewed-by: Minh Diep <mdiep@whamcloud.com>
Reviewed-by: James Simmons <jsimmons@infradead.org>
Reviewed-by: Oleg Drokin <green@whamcloud.com>