Currently, in the non-multiservice FTDC schema, the FTDCMetadataCompressor only computes deltas up to 2 levels down the sample BSON object. This is incompatible with the new multiservice FTDC schema, where the actual metrics that need to be compressed are pushed down one level deeper in the BSON object sample. Modify the FTDCMetadataCompressor delta algorithm to be multiservice schema-aware & compress accordingly.