debian: add rc script

This was moved from targetcli to rtslib,
using targetctl.

Signed-off-by: Johannes Dewender <github@JonnyJD.net>
debian: update control with breaks/replaces

The target rc script is replaced with the one in rtslib.

Signed-off-by: Johannes Dewender <github@JonnyJD.net>
debian: patch targetctl to use python3

Signed-off-by: Johannes Dewender <github@JonnyJD.net>