Si(Total)Charge changes to improve iterability

• Moved from std::list to std::vector for SiTotalCharge backend container to improve speed due to prefetching
• Moved to functions from std::algorithm to improve maintainability and readability (and possibly speed)

Tagging @tdado

Functional change where backend container (std::list with a custom SG::ArenaSharedHeapSTLAllocator<SiCharge>) is replaced by std::vector and default allocator. Need experts to confirm this is okay!

Pixel digitization output with radiation damage compared via diff-root - is the same