Migrate to binary for disk decryption in initramfs

live_exam_os/.gitignore

live_exam_os/Dockerfile

live_exam_os/config/01-packages_install/packages

.../config/02-customisation/etc/initramfs-tools/hooks/unlock

...config/02-customisation/etc/initramfs-tools/scripts/nexus

...s/config/02-customisation/etc/initramfs-tools/scripts/pxe

...config/02-customisation/etc/initramfs-tools/scripts/tools

live_exam_os/config/03-post_install/5000-push_challenge.sh

live_exam_os/config/03-post_install/7000-unlocker.sh

live_exam_os/config/03-post_install/8000-initramfs.sh

live_exam_os/tigress_4.0.10-1_all.deb.zip

live_exam_os/tools/functions.sh

live_exam_os/tools/unlocker.c