feat(core): Migrate request data to `dataCollection` (#21071)

- `httpHeadersToSpanAttributes()` now accepts `ResolvedDataCollection`
and delegates filtering
to `filterKeyValueData()` from the data-collection utils instead of
reimplementing deny/allow logic.
Boolean (`sendDefaultPii`) is still accepted for backward compat with
external callers (TODO for v11 removal).

- `requestDataIntegration` reads `client.getDataCollectionOptions()`
instead of `client.getOptions().sendDefaultPii`.
`DEFAULT_INCLUDE` is now derived from `dataCollection` at call time,
with integration-level `include` options
    overriding per spec.

- `server-subscription.ts` passes `client.getDataCollectionOptions()` to
header attribute creation
  
  closes https://github.com/getsentry/sentry-javascript/issues/21048