Should persist blueprint reports #8788
Description
#8631 introduces a notion of a "planning report", which is structured information about a planning run that produced a particular blueprint. In that first version, they are ephemeral: they are produced by do_plan, and are returned from the blueprint_planner background task so that omdb may print them, but they are not stored persistently.
They should instead be stored in the Cockroach database and subsequently read out by blueprint_read. This will add (significant) overhead to changing the reports; it may be worth considering tooling or alternate representations to reduce that overhead. They should probably also be garbage collected along with their associated blueprints.