feat(Checkpoints): consume canonical audience configuration

[rickvdl]

Description

With this PR we're now reading one static blob with all audience rules from the remote config infrastructure, as well as an object of backend_predicate_results, which contains the backend computed facts that we should fill in at the placeholders in the rules of the audiences blobs.

Changes

This PR contains the following:

• Fetching, decoding, storing and caching the static blob of audiences through the existing remote config infrastructure
• Reading and decoding the backend_predicate_results object from the audiences topic. This object is kept in memory for easy access.
  • We'll be using bool's for now, but any value that works in the rules evaluator (DimensionValue) should work here, for future extensibility.
• The facts from backend_predicate_results are passed into the rules evaluator through the backendValues. Ensuring that these values are used in rules (through the backend.* dimension) where these variables are mentioned

Related Android PR

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Note

Medium Risk
Changes checkpoint targeting, remote-config key handling, and audience loading paths; mis-decoding or generation mismatches could cause incorrect matches or spurious configuration-unavailable outcomes.

Overview
Checkpoint resolution now loads one generation-bound audience snapshot (rules from the default blob plus inline backend_predicate_results) instead of looking up audiences live, and passes subscriber-specific facts into rule evaluation as backend.* dimensions alongside custom.*.

Checkpoint workflow resolver retries resolution once when checkpoint or audience config goes stale mid-flight, keeps checkpoint rules and audience data on the same config generation, and feeds backendPredicateResults into the local rules matcher so audience predicates can reference hashed backend placeholders.

Remote config decoding preserves exact wire keys in ConfigItem.content (including opaque condition hashes and snake_case fields like offering_identifier), which workflows and audience metadata rely on. AudiencesConfigProvider decodes the canonical audience map from the prefetched blob, tolerates per-audience decode failures, and converts supported AnyDecodable values to DimensionValue for rules.

Tests cover retry/stale behavior, backend predicate matching (booleans and other dimension types), and the new audiences topic shape.

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[RevenueCat-Danger-Bot]

⚠️ Warnings

This PR changes 396 lines of production Swift (limit 300); skipped via skip-pr-lines-changed-check label.

[rickvdl]

@RCGitBot please test

[tonidero]

This makes sense! Just some non-blocker comments

[ajpallares]

I added some more comments!

[rickvdl]

@RCGitBot please test

[rickvdl]

@RCGitBot please test

[rickvdl]

@RCGitBot please test