Use HeaderConstants for CRC64 InvalidHeaderValue payload

[Copilot]

This addresses the PR review comment on the CRC64 transactional checksum path. The InvalidHeaderValue details for malformed x-ms-content-crc64 input now use the shared blob header constant instead of an inline string literal.

• What changed

  • Updated computeAndValidateTransactionalChecksums in src/blob/utils/utils.ts to use HeaderConstants.X_MS_CONTENT_CRC64 when constructing the InvalidHeaderValue payload.
  • Added the corresponding HeaderConstants import from src/blob/utils/constants.ts.

• Why this matters

  • Keeps header naming aligned with the rest of the blob handlers.
  • Reduces drift/typo risk in error payloads for transactional checksum validation.

• Code sketch

  throw StorageErrorFactory.getInvalidHeaderValue(contextId, {
    HeaderName: HeaderConstants.X_MS_CONTENT_CRC64,
    HeaderValue: expectedCrc64RawHeader ?? ""
  });