(PDB-747) Initial schema for structured facts support

This patch adds an initial schema for structured facts support.

Signed-off-by: Ken Barber <ken@bob.sh>
(PDB-708) Structured fact storage

Here we add the initial work required to start storing structured facts in
its new schema.

Signed-off-by: Ken Barber <ken@bob.sh>
(PDB-708) Add removal of sequences to clear-db-for-testing!

We has started to declare sequences outside of table creation so we get great
control. However the testing code doesn't expect this, and clearing tables
will not clear this manually created sequences. This path adds the functionality
to scan and drop sequences during testing.

Signed-off-by: Ken Barber <ken@bob.sh>
This changes the structured-facts migration to move data from the previous
schema to the new.