Redesign of transaction and transaction fees logic

[jorgenbuilder]

Currently we refund transaction fees when mints fail. This may create an attack vector where an attacker could drain the canister funds through transaction fee refunds with an NFT canister that's designed to fail.

To mitigate this, we should make the user cover the transaction fees.

This could lead to an issue where failed mints would result in lost ICP transaction fees. This can be resolved with an internal ICP lock system that defers and real ICP transfer until after a successful mint.

[q-uint]

A draft: https://github.com/sagacards/bazaar/tree/experimental/locks (f2b0218)