MaterialEffectsOnTrack: Use optional for the Scattering angles, and unique_ptr for the energy Loss. Migrate clients to passing Scattering angles accordingly so as to avoid too many allocations

MaterialEffectsOnTrack:

• Use optional for the Scattering angles since this is a "plain type".
• unique_ptr for the energy Loss as this seems to be polymophic type.

Migrate clients to passing the ScatteringAngles accordingly so as to avoid too many allocations i.e avoid new

Mentioning @sroe