Signed-off-by: NPaul Tötterman <paul.totterman@iki.fi>

Signed-off-by: NRemi Reuvekamp <git@remireuvekamp.nl>

* Add contexts to device database

* Remove spurious whitespace

* Add prefixes to namespace the SQL tables.

This means that multiple components can share a single database schema
without colliding with each other.

Once this lands it will be possible to run a single monolithic dendrite
against a single postgresql schema.

Hopefully this will make trivial deployments and development easier.

* Comment