Add Tag to RemoveSecurity Method

[AlexCatarino]

Expected Behavior

The RemoveSecurity has a tag parameter. The tag will be used in the CancelOpenOrders and Liquidate to inform the user of the cause of cancellation/liquidation.

Actual Behavior

If we see a Liquidate tag, we don't know if it came from RemoveSecurity or Liquidate methods

Potential Solution

Add tag parameter, update CancelOpenOrders and Liquidate calls.

Checklist

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