Moving total_count field from SegmentStatistics to CustomerSegmentMemberConnection

As of 2023-07, you can use total_count on CustomerSegmentMemberConnection endpoint, which will provide you with the total count of your specified customer segment. Also, as of 2023-07, we're removing total_count field on SegmentStatistics. Using the total_count functionality will make it easier to know the count of members of your specified segment.