This function should send 'clone' with the list of sharded collections as 'collsToIgnore' to the new primary shard specified in the movePrimary request.

TBD: How should the current primary get the list of sharded collections to send in 'collsToIgnore'?

• Should it read config.collections?
• Should the config server pass 'collsToIgnore' in its movePrimary request to the current primary?
• Should the target primary just read config.collections itself?