Function serializedEntityLocationTables

Build the per-quadrant serialized location tables (the shape core fromData consumes) from a flat list of live persistent entity locations.

A persistence layer mirrors entity locations keyed by entity id; on load it hands that flat set here and this buckets each entity into its persistent quadrant's local-index table. This keeps all quadrant/id-encoding knowledge inside @adobe/data — callers never touch the bit layout.