[Refactor] Centralize planner and backend accuracy formulas

[milindsrivastava1997]

What to build

Centralize the shared CMS, HLL, KLL, and DDSketch accuracy formulas in asap_types, with a small interface over normalized family parameters. The control plane and data plane should retain only their source-specific parameter extraction and any backend-only augmentation, then derive the same AccuracyProfile through the shared formulas.

This removes the current duplicated policy logic while preserving the physical-plan compile, publish, install, and serving behavior.

Acceptance criteria

• Each shared sketch-family formula has one authoritative implementation in asap_types.
• Control-plane planning and data-plane serving derive equivalent AccuracyProfile values for identical normalized CMS, HLL, KLL, and DDSketch inputs.
• Backend-specific behavior remains outside the shared formula module and is covered by focused tests.
• A cross-crate parity test covers representative parameters for every supported shared family.
• Existing physical-plan and query-serving tests continue to pass.

Blocked by

None - can start immediately

[milindsrivastava1997]

pls check @zzylol if this makes sense