update to proxmox-sys 0.2 crate

- imported pbs-api-types/src/common_regex.rs from old proxmox crate
- use hex crate to generate/parse hex digest
- remove all reference to proxmox crate (use proxmox-sys and
  proxmox-serde instead)

Signed-off-by: Dietmar Maurer <dietmar@proxmox.com>

src/tools/disks/zfs.rs

@@ -34,7 +34,7 @@ pub fn zfs_pool_stats(pool: &OsStr) -> Result<Option<BlockDevStat>, Error> {
     path.push(pool);
     path.push("io");
 
-    let text = match proxmox::tools::fs::file_read_optional_string(&path)? {
+    let text = match proxmox_sys::fs::file_read_optional_string(&path)? {
         Some(text) => text,
         None => { return Ok(None); }
     };