Depend on bsdextrautils, for hexdump (used during testing)

* Add to Build-Depends
* Add to ostree-tests Depends
* Allow bsdmainutils (<< 12) as an alternative, for backports

debian/control

@@ -11,6 +11,7 @@ Build-Depends:
  autoconf,
  automake,
  bison,
+ bsdextrautils <!nocheck> | bsdmainutils (<< 12) <!nocheck>,
  ca-certificates,
  cpio,
  debhelper-compat (= 12),
@@ -179,11 +180,11 @@ Description: libostree boot loader and initramfs integration
   - the boot loader must be one that is supported by libostree, currently
     GNU GRUB 2, syslinux/extlinux or Das U-Boot
 
-
 Package: ostree-tests
 Architecture: linux-any
 Depends:
  attr,
+ bsdextrautils | bsdmainutils (<< 12),
  ca-certificates,
  cpio,
  fuse,