Fix malloc, calloc and realloc

[powware]

calloc and realloc only track the size that has been requested by the user, when realloc then forwards the size to ReallocatePool the sizeof(size_t) is missing and the memcopy of ReallocatePool misses these bytes.

Addtionally calloc only tracks the size parameter where it should instead track the product of nmemb and size.

I rewrote malloc, calloc and realloc to track the true size in memory for easier handling.

[pbatard]

Good call! Sorry for the delay in replying to your PR, as I must admit it fell through my list of notifications.

I'll be updating this project in the coming days, due to the release of 2022.10.3 upstream, and I'll make sure to integrate your changes. Thanks again!