[CBM] Save heap information as part of stats

What is the problem?
We have statistics for system and process memory use which can be helpful in CBSEs. We can also create a heap profile with environment variables. This requires customer intervention though, so it would be nice to report more information like this by default.

What is the solution?
We should include runtime.MemStats in the stats that we output. This will give us a more accurate insight into our memory usage and could be used to validate the garbage collector is running correctly