[AutoOps] Cache Template Hash to avoid resending

Templates can be quite large, so resending them -- even just daily -- is wasteful if nothing has changed.

The AutoOps module should record a hash for each template that it ships and upon the next poll, it should ignore templates whose hash does not change. In a first implementation, we can maintain these hashes in memory (name -> hash) and then in future enhancements we can write it to a stateful file to try to survive across restarts.