BugLink: https://bugs.launchpad.net/bugs/1861284

Add new dkms-build scripting which prepares a kernel headers tree and
then builds specified DKMS packages against those headers.  The
resulting .kos are then incorporated into the specified package,
including signing them into this kernels module signing key.  This
allows them to be loaded in a secure-boot environment.

Squashes the following commits from bionic:

  UBUNTU: update dkms package versions
  UBUNTU: [Config] wireguard -- enable for all architectures
  UBUNTU: [Packaging]: ignore wireguard modules when wireguard is disabled
  UBUNTU: [Packaging] wireguard -- add support for building signed .ko
  dkms-build: apt-cache policy elides username:password information
  UBUNTU: [Packaging] file-downloader not handling positive failures correctly
  UBUNTU: temporarily drop Built-Using data
  UBUNTU: [packaging] handle downloads from the librarian better
  UBUNTU: [Packaging] autoreconstruct -- manage executable debian files
  UBUNTU: [Packaging] Fix config file assembly
  UBUNTU: [Packaging] dkms -- dkms-build quieten wget verbiage
  UBUNTU: [Packaging] dkms -- try launchpad librarian for pool downloads
  UBUNTU: [Packaging] dkms-build -- backport latest version from disco
  UBUNTU: [Packaging] dkms-build -- add support for unversioned overrides
  UBUNTU: [Packaging] dkms-build: do not redownload files on subsequent passes
  UBUNTU: [Packaging] dkms-build -- support building against packages in PPAs
  UBUNTU: [Packaging] dkms -- switch to a consistent build prefix length and strip
  UBUNTU: [Packaging] dkms -- add per package post-process step
  UBUNTU: [Packaging] dkms -- dkms package build packaging support
Signed-off-by: Andy Whitcroft <apw@canonical.com>
Acked-by: Kleber Sacilotto de Souza <kleber.souza@canonical.com>
Acked-by: Stefan Bader <stefan.bader@canonical.com
Signed-off-by: Ian May <ian.may@canonical.com>
Signed-off-by: Kelsey Skunberg <kelsey.skunberg@canonical.com>