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/bin/proxmox-backup-api.rs

@@ -10,7 +10,7 @@ use http::HeaderMap;
 
 use proxmox_lang::try_block;
 use proxmox_router::{RpcEnvironmentType, UserInformation};
-use proxmox::tools::fs::CreateOptions;
+use proxmox_sys::fs::CreateOptions;
 
 use proxmox_rest_server::{daemon, AuthError, ApiConfig, RestServer, RestEnvironment, ServerAdapter};