add protected info of snapshots to api and task logs

adds the info that a snapshot is protected to:
* snapshot list
* manual pruning (also dry-run)
* prune jobs

Signed-off-by: Dominik Csapak <d.csapak@proxmox.com>
Signed-off-by: Wolfgang Bumiller <w.bumiller@proxmox.com>

tests/prune.rs

@@ -19,8 +19,8 @@ fn get_prune_list(
 
     prune_info
         .iter()
-        .filter_map(|(info, keep)| {
-            if *keep != return_kept {
+        .filter_map(|(info, mark)| {
+            if mark.keep() != return_kept {
                 None
             } else {
                 Some(info.backup_dir.relative_path())