Kahadb pagefile, allocated and unused pages from read only transactions are leaked

The work in AMQ-7080 to checkpoint the free list has identified a case where the free list is not updated to reflect the disk state of an allocated free page. This can lead to a free page leak in error. In practice this pattern of usage is not widely used, but it is relevant when the free page list is being tracked and failure can be arbitrary. It is important that an accurate reflection of the current state is being checkpointed.