DataSent and DataQueued events should be handled gracefully in the TransferFinished state

[aarshkshah1992]

• After a data-transfer restart, Graphsync can still call the OnDataSent hook for blocks that have already been sent which in turn will fire the DataSent data-transfer event. The same applies to the DataQueued event.
• To ensure we don't double count data sent, we introduced a DataSentProgress and a DataQueuedProgress events a while ago in Dont double count data sent #185. These events are only emitted the first time we send a block to a remote peer.
• Thus, if a data-transfer restarts after entering the TransferFinished state, we can still receive DataSent and DataQueued events for blocks that have already been sent. We need to handle these events gracefully in the TransferFinished state.