UBUNTU: [Packaging] Add a new fips-checks script

UBUNTU: [Packaging] Add a new fips-checks script

BugLink: https://bugs.launchpad.net/bugs/1945989
Add a new script responsible for checking if any FIPS relevant commit
was added since the last version. If a new change is found, a
corresponding entry should exist in the justifications file otherwise
the check will fail.

The justifications file is located at "${DEBIAN}/fips.justifications"
and should follow the following format for each commit justification:

<commit short message>

  <commit justification>

Signed-off-by: Marcelo Henrique Cerri <marcelo.cerri@canonical.com>
Acked-by: Tim Gardner <tim.gardner@canonical.com>
Acked-by: Stefan Bader <stefan.bader@canonical.com>
Signed-off-by: Kelsey Skunberg <kelsey.skunberg@canonical.com>