When there is a moveChunk from one shard to another, in the migration_destination_manager.cpp (cloning indexes phase), the recipient shard is not waiting for in-progress index builds to be finished.

More in particular, the logic of filtering the existing indexes on the destination shard, is using removeExistingIndexesNoChecks that filters out read and in-progress indexes.

If the recipient shard assumes that in-progress indexes are already created indexes, we could potentially end up in a situation where the index is not finally created in that shard. There is no guarantee that in-progress index build to succeed.

The goal of this ticket is to fix that behaviour. In order to make that, we could make moveChunk wait for in-progress index build to be finished on the recipient shard.