replace Userid with Authid

in most generic places. this is accompanied by a change in
RpcEnvironment to purposefully break existing call sites.

Signed-off-by: Fabian Grünbichler <f.gruenbichler@proxmox.com>

src/bin/proxmox-backup-manager.rs

@@ -388,7 +388,7 @@ fn main() {
 
 
     let mut rpcenv = CliEnvironment::new();
-    rpcenv.set_user(Some(String::from("root@pam")));
+    rpcenv.set_auth_id(Some(String::from("root@pam")));
 
    proxmox_backup::tools::runtime::main(run_async_cli_command(cmd_def, rpcenv));
 }