Parse marketplace feed processing reports and retry partial failures

Steps

1. After `getFeed` returns `processingStatus: DONE`, call `getFeedDocument` with the `resultFeedDocumentId` to get a signed download URL for the report.
2. Fetch the report document and decompress it if the `compressionAlgorithm` field in the feed document response indicates GZIP encoding.
3. Parse the JSON processing report: the top-level `header` contains `messageCount` and `acceptedCount`; each item in the `messages` array has a `messageId`, `processingStatus` (ACCEPTED, INVALID, etc.), and an `issues` array.
4. Filter messages where `processingStatus` is not ACCEPTED; for each, inspect `issues` entries for `code`, `severity`, and `message` to determine the root cause.
5. Categorize failures: data errors (invalid attribute values, missing required fields) require data correction; system errors (throttling, timeout) are safe to retry without changes.
6. Re-submit corrected records in a new feed, mapping each corrected record back to its original SKU using the `sku` field in the message body.