tape: implement binding for libsgutils2

So that we can read cartridge memory without calling "sg_raw". In future,
we may need further low level command to control the tape..

src/tape/mod.rs

@@ -7,6 +7,8 @@ use proxmox::tools::fs::{
     CreateOptions,
 };
 
+pub mod sgutils2;
+
 pub mod file_formats;
 
 mod tape_write;