api2/tape: add api call to list media sets

we want a 'media-set' selector in the gui, this makes it
very easy to do and is not as costly as reusing the media list,
since we do not need to iterate over all media (e.g. unassigned)

Signed-off-by: Dominik Csapak <d.csapak@proxmox.com>

src/api2/types/tape/media.rs

@@ -12,6 +12,26 @@ use crate::api2::types::{
     MediaLocation,
 };
 
+#[api(
+    properties: {
+        "media-set-uuid": {
+            schema: MEDIA_SET_UUID_SCHEMA,
+        },
+    },
+)]
+#[derive(Serialize,Deserialize)]
+#[serde(rename_all = "kebab-case")]
+/// Media Set list entry
+pub struct MediaSetListEntry {
+    /// Media set name
+    pub media_set_name: String,
+    pub media_set_uuid: Uuid,
+    /// MediaSet creation time stamp
+    pub media_set_ctime: i64,
+    /// Media Pool
+    pub pool: String,
+}
+
 #[api(
     properties: {
         location: {