Optimization: group actions by callable, create tasks in batches for performance

[davidshaw-uw]

If we conceptualize actions as instances of a given callable, we can group actions by callable to create jobmon tasks in bulk. This might make the task creation faster since we don't have to set upstreams and create metadata for each lone object, but rather in groups.

Idea:

action_map = defaultdict(defaultdict(list)))
for action in self.action_generator():
     action_map[action.name].update(action.kwargs)

for action_name, kwargs in action_map.items():
     task_template = TaskTemplateFactory.get_task_template(action_name)
     task_template.create_tasks(**kwargs)