implement move images command

- Also implement various importantr bugfixes for shutdown handling

src/pus/stack.rs

@@ -27,6 +27,7 @@ impl PusStack {
             .expect("time stamp generation error")
             .to_vec()
             .unwrap();
+        let mut loop_count = 0;
         loop {
             let mut nothing_to_do = true;
             let mut is_srv_finished =
@@ -69,6 +70,12 @@ impl PusStack {
                 self.mode_srv.poll_and_handle_next_tc(&time_stamp),
                 Some(self.mode_srv.poll_and_handle_next_reply(&time_stamp)),
             );
+            // Safety mechanism to avoid infinite loops.
+            loop_count += 1;
+            if loop_count >= 500 {
+                log::warn!("reached PUS stack loop count 500, breaking");
+                break;
+            }
             if nothing_to_do {
                 // Timeout checking is only done once.
                 self.action_srv_wrapper.check_for_request_timeouts();