Pipeline task management

Session persists a collection of tasks with unique identifiers; shared pipeline caller can optionally enqueue its call as a task instead of running it directly

model_server/base/api.py

@@ -234,4 +234,6 @@ def list_tasks() -> Dict[str, TaskInfo]:
 @app.put('/tasks/run/on_files')
 def task_file_batch():
     # new callable that parameterizes file name to acc_id, then passes this to to /tasks/*/run
-    pass
\ No newline at end of file
+    pass
+
+# TODO: tasks to run all enqueued items
\ No newline at end of file