NO-ENDPOINT: update notifier to look at doc_type

[darmstrong-r7]

This PR updates notifier to look at doc_type for notifications.

[scudette]

The way notifications work is as a toggle switch. That means you get multiple notifications the receiver will only get a single notification.

That's why we just write to a doc id and then read it periodically. It doesn't matter how many times we write to it but we only notify once.

When we folded all the records into the same index the doc id clashed. So here we need to uniquify the doc id by adding a suffix like "_notify" for example.