HerculesBox overhaul

Several improvements are needed for HerculesBox:

1. Support products
2. If the user wants to create the box from existing memory (a slice, Vec, etc.), ensure it is properly aligned (or copy into aligned memory) (!190 (merged)) hercules_rt now enforces a global allocator that aligns allocations as needed
3. Allow users to use HerculesBox like a Box and in provides ways to allocate memory using HerculesBox and then modify the values it holds with the benefit being that it avoids potentially copying to correct alignment that can result from allocating using a Vec and then creating the box. This will replace the AlignedSlice currently used in cfd.