In disaggregated storage, the maximum consecutive delta is set to 32. Therefore, a uint8_t is enough to cover the max count of deltas. But in the PALI interface, we use a size_t for delta count. We should investigate can we use uint8_t for delta count instead of size_t.

To save memory, at the btree level, we use a uint8_t to store the delta count. This means we need to do a cast from size_t to uint8_t when we store the delta count information in btree. If we change the API to also use uint8_t, we can remove this cast.

The risk of doing this is that we may increase the maximum consecutive delta to more than 255 in the future. But I think that is very unlikely.