introduce framework class, introduce autodelete announcement on shutdown

nostr_dvm/utils/backend_utils.py

@@ -192,11 +192,3 @@ def get_amount_per_task(task, dvm_config, duration=1):
             0].NAME + "] Task " + task + " is currently not supported by this instance, skipping")
         return None
 
-
-def keep_alive():
-    try:
-        while True:
-            time.sleep(10)
-    except KeyboardInterrupt:
-        os.kill(os.getpid(), signal.SIGKILL)
-        exit(1)