Delete entries, assets, and content types that exist in production that doesn't in staging #1
Description
Right now we get the differences in one direction (from staging to production) to figure out which pieces of data exist or have been updated in staging that hasn't been synced with production. To figure out which pieces of data need to be removed, we need to do diff from production to staging. The removal of this data should probably occur before the upserting of the content.