Remove det surgery

Notes:
* deploying this change will require some app downtime (probably several hours) as the `detection_extract_view_mv` needs to be re-built and re-indexed.
* this should fix #110 
<pre>
...
left join <b>device tag</b> on sensor.tag_id = tag.id
...
</pre>

Is that right? there seems to be too many terms there, to me.