CP-8784: Support fd mappings in cancellable_subprocess

Signed-off-by: Si Beaumont <simon.beaumont@citrix.com>
CP-8784: Use new suspend-image format

Signed-off-by: Si Beaumont <simon.beaumont@citrix.com>
DEBUG: Log Domain.{suspend,resume} with different ident

Signed-off-by: Si Beaumont <simon.beaumont@citrix.com>