materialize all key (mapped in QGIS layer file) model output views

[smnorris]

A nice simple way to keep outputs stable while processing is being done in the background.
Only drawback is that materializing streams_vw takes up a lot of space but I think it is worth it, model runs can happen with no down time of outputs.

[smnorris]

Note that a db schema update will cascade various drops to the materialized views and still result in down time.