Part of #5420. Phase 1 — foundation.

Add the internal resolved config and the legacy bridge; make it the single read path.

• Internal ResolvedDataCollection (all fields populated), resolved once at SDK init and exposed internally (e.g. via SentryOptions).
• Resolution precedence: (1) fields explicitly set on DataCollection; (2) if DataCollection is set at all, missing fields use the new spec defaults (UserInfo=true, all HttpBodies, denyList behaviors, FrameContextLines=5); (3) if DataCollection is absent, derive everything from SendDefaultPii:
  • true → everything on.
  • false/unset → UserInfo=false, HttpBodies=None, GenAI off, DatabaseQueryData=false, deny-lists extended with GDPR terms (forwarded, -ip, remote-, via, -user).
• If both DataCollection and SendDefaultPii are set, SendDefaultPii is ignored.
• No consumer migrated yet — that happens per-area in Phase 2.

JS references: resolveDataCollectionOptions.ts, defaultPiiToCollectionOptions.ts (getsentry/sentry-javascript#20967, getsentry/sentry-javascript#20970).