The MoveUnshardedPolicy is used to issue random migrations of unsharded collections in "with_balancing" suites and is currently allowed to fail with any error since the method handling responses is empty.

Purpose of this ticket is to define a list of errors moveCollection is expected to fail on. Some error codes to probably take into account:

• NamespaceNotFound if the collection does not exist
• NotImplemented if called on timeseries (or maybe no since the feature flag is enabled?)
• CommandNotSupported during upgrade/downgrade
• Others from src/mongo/db/s/config/configsvr_reshard_collection_cmd.cpp ?