feat: remove untracked debootstrap sources

Current debootstrap is copy pasted from debian sources and dirty patched to make it work with fs-cook and its without any tracking from original debootstrap remote. Its better to add sources with git submodule (will be done in future commits) and find alternative way to make debootsterap work with fs-cook (DEBOOTSTRAP_DIR should do the magic)

Author: SaicharanKandukuri