Use system memory allocator

[mwtian]

This switches memory allocator to the system provided allocator for running Sui nodes. jemalloc can be loaded dynamically instead, so the C++ logic will be able to use jemalloc as well. This has the benefits that C++ allocations can be profiled, and there might be less fragmentation (I believe in Facebook rocksdb is used with jemalloc).

Image build is tested at https://github.com/MystenLabs/sui-operations/actions/runs/3339609372