How to unlock depositing after a 100% seize on the pool

[pdyraga]

Consider the following scenario:

• 1 T is deposited into the asset pool.
• The risk manager seizes 1 T (100% of the pool).
• There is 1 covT in existence and 0 T deposited in the asset pool.

When someone tries to deposit in this state, the transaction will revert because collateralBalance is 0:

coverage-pools/contracts/AssetPool.sol

Lines 584 to 599 in 71047ca

	/// @dev Calculates underwriter tokens to mint.
	function _calculateTokensToMint(uint256 amountToDeposit)
	internal
	returns (uint256)
	{
	rewardsPool.withdraw();
	uint256 covSupply = underwriterToken.totalSupply();
	uint256 collateralBalance = collateralToken.balanceOf(address(this));
	if (covSupply == 0) {
	return amountToDeposit;
	}
	return (amountToDeposit * covSupply) / collateralBalance;
	}

The pool can be unlocked by depositing some amount of T and I think this was the original intention when implementing this piece of code - it is hard to come up with _calculateTokensToMint value if there is nothing deposited but the covT supply is non-zero.

We should revisit this decision or at least make it clear in the docs what should be done after the 100% seize event.