[SPIKE] Design changes to remove redundant rollups

As a swatch dev, I'd like to reduce noise/redundancy in stored tally data).

Especially in the PAYG use-case, the rollup records having

{sla,usage,billing_marketplace,billing_account_id}

=_ANY are easily reproduceable, and thus provide no actual value.

Potentially in scope options:

• filter out before repository.save
• refactor logic so _ANY data not even produced
• remove existing data

DONE

• proposal has been reviewed by devs, and cards created as necessary