Update CurrencySettler to use SafeERC20

[ivanvolov]

Motivation

The CurrencySettler is used to create custom hooks, but it's not working with tokens like USDT.

Details

Update CurrencySettler to use safeTransfer and safeTransferFrom instead of transfer and transferFrom.

        } else {
            manager.sync(currency);
            if (payer != address(this)) {
                IERC20(Currency.unwrap(currency)).safeTransferFrom(payer, address(manager), amount);
            } else {
                IERC20(Currency.unwrap(currency)).safeTransfer(address(manager), amount);
            }
            manager.settle();
        }