LU-17000 contrib: script to prepare coverity builds

LU-17000 contrib: script to prepare coverity builds

Add script 'coverity-run' to semi-automate running
and submitting Coverity builds for Lustre. This
should make it much easier to reproducibly submit
builds to Coverity - and serve as an example of
how the Coverity build process works. It should
also provide more transparency in how builds are
being prepared for Coverity.

Add a Vagrantfile for the Vagrant VM used during
the build process.

Update in-tree Documentation.

Test-Parameters: trivial
Signed-off-by: Timothy Day <timday@amazon.com>
Change-Id: I050b10d9df0e4e4c1b8bcc91a3c296c11f27ffef
Reviewed-on: https://review.whamcloud.com/c/fs/lustre-release/+/53400
Tested-by: jenkins <devops@whamcloud.com>
Tested-by: Maloo <maloo@whamcloud.com>
Reviewed-by: Andreas Dilger <adilger@whamcloud.com>
Reviewed-by: Arshad Hussain <arshad.hussain@aeoncomputing.com>
Reviewed-by: Oleg Drokin <green@whamcloud.com>