refactor deviceList

• add constructor using Foam::zero type in deviceList and deviceField to handle special case of a field initialized to zero with Foam::Zero;
• specialized deviceList::memSet function to handle reccurrent pTraits::one and pTraits::zero special cases without newer constructors in deviceField;
• added lower level memset specialized functions in memory pool;
• refactor of nu deviceField initialization in deviceIcoFoam;
• remove cudaDeviceSynchronize calls;