Entity Columns for Aggregates

[dmdashenkov]

Currently, Entity Columns feature is available only for Projections. It's required to add support for Aggregates (in StandStorage).

For more info, see Stand.update().

[dmdashenkov]

This should be implemented at least partially for archived and deleted columns, which are present effectively at any entity type.

This change should eliminate double-faced nature of the RecordStorage API: currently, it has two ways of writing a record, with and without entity columns.

[dmdashenkov]

By now, aggregates have acquired a mirror projection in the system context. The entity columns should be mirrored to the projection as well, since the projections are queried for the aggregate states now.

[armiol]

Addressed in 2.0 snapshots.