Renames

As this repository will be hosting the ci scripts for blktap, some
functions need to be renamed, to reflect that they are not coupled to
sm.
Refactor: sm_pack_create -> source_pack_create
refactor: smroot_restore -> chroot_restore
Refactor: smroot_create -> chroot_create
Refactor smroot_dump -> chroot_dump
Refactor: rename

smroot_install_prereqs -> chroot_install_sm_prereqs
Refactor: rename

smroot_prepare_venv -> chroot_prepare_sm_venv
Refactor: rename

smroot_run_tests -> chroot_run_sm_tests