Add Escape Hatch

[auryn-macmillan]

On multiple occasions, we have run into issues where some issue has prevented us proving the round on chain in a way that will let us finalize the round and pay out to recipients.

To avoid this outcome in future, we should add an escapeHatch() that allows owner to extract all funds from the contract.

We should also add a lockEscapeHatchAndThrowAwayKey() (or similar) function for instances of clr.fund that do not wish for owner to have the power to extract funds.