Allow non-zero price discovery buyer cancelation for price discovery offers

[zajck]

Currently, price discovery offers require its price to be set to zero:

boson-protocol-contracts/contracts/protocol/bases/OfferBase.sol

Line 153 in b131a97

if (_offer.priceType == PriceType.Discovery && _offer.price != 0) revert InvalidPriceDiscoveryPrice();

This is to ensure that the offerPrice in releaseFunds is correct in all subsequent calculations. If we didn't require zero price at offer creation time, we'd need to handle it here.

boson-protocol-contracts/contracts/protocol/libs/FundsLib.sol

Line 131 in b131a97

uint256 offerPrice = offer.price;

As a consequence, the buyer cancellation penalty is restricted to 0

boson-protocol-contracts/contracts/protocol/bases/OfferBase.sol

Line 238 in b131a97

if (_offer.buyerCancelPenalty > offerPrice) revert InvalidOfferPenalty();

This imposes restrictions for price discovery offers, while at the same time buyer cancellation penalty works ok with the static offers, even when they are used in secondary commit. All that needs to be checked is that the actual price is high enough to cover cancellation penalty:

boson-protocol-contracts/contracts/protocol/facets/SequentialCommitHandlerFacet.sol

Line 109 in b131a97

if (thisExchangeCost.price < offer.buyerCancelPenalty) revert PriceDoesNotCoverPenalty();

We should allow for buyer cancellation penalty in price discovery offers as well. It would then also serve as some sort of reserved price, since the protocol won't allow lower prices.
Steps to enable it:

• remove restrictions in storeOffer
• properly handle offerPrice in releaseFunds
• add check-in commitToPriceDiscoveryOffer to make sure actualPrice is greater than the buyer cancellation penalty. Maybe the check can be moved into priceDiscoveryBase, so that both the price discovery handler and sequential commit handler would use the same code.