CSHARP-956 Aggregate command can not be sent to a secondary if it uses $out

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• Closed

PYTHON-1665 PyMongo should send aggregate commands with $out to primary nodes

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• Closed

CDRIVER-2886 Aggregate command must be sent to a primary if it uses $out

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• Closed

CXX-1696 Aggregate command must be sent to a primary if it uses $out

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• Closed

MOTOR-289 Aggregate command must be sent to a primary if it uses $out

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• Closed