v2.0.0-rc.9

Substreams fixes

Note All caches for stores using the updatePolicy set_sum (added in substreams v1.7.0) and modules that depend on them will need to be deleted, since they may contain bad data.

• Fix bad data in stores using set_sum policy: squashing of store segments incorrectly "summed" some values that should have been "set" if the last event for a key on this segment was a "sum"
• Fix small bug making some requests in development-mode slow to start (when starting close to the module initialBlock with a store that doesn't start on a boundary)