Loop the DuplicateKeyTracker into the hybrid index build process and have background, unique indexes use the hybrid index build code.
- depends on
- 
                    SERVER-37268 Change BG index build to use the Bulk builder and external sorter -         
- Closed
 
-         
- is depended on by
- 
                    SERVER-37264 Replace BG index build logic with new IAM -         
- Closed
 
-         
- related to
- 
                    SERVER-43410 MultiIndexBlock::_dumpInsertsFromBulk not used or implemented -         
- Closed
 
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