AC

• Implement spec changes for the handshake error handling and unskip tests tagged with NODE-3135

• Depending on the scope of the work, in this ticket or a follow up: update the staleness check to read connection generation from the error instead of the connection, since we want it to be able to handle errors that occur while establishing a connection, too; this requires injecting the connection generation into the error in the `createConnection` method (or elsewhere down the chain); the staleness check should be added to the `handleError` logic