use constants struct for small velo ut LUTs

• rename GpuConstants into Constants -> also save host constants for those algorithms running on both architectures
• save ut_dxDy in LUT in Constants, rather than using an un-safe function for it
• delete VeloUTTracking::HitsSoA.cos, rather calculate it from ut_dxDy when needed -> save space

marked as a Work In Progress

changed the description

added 2 commits

• 0965ca10 - remove unused functions in VeloUTDefinitions.cuh
• f66cb749 - remove functions to access array members of VeloUTTracking::HitsSoA

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unmarked as a Work In Progress

merged

mentioned in commit 19d44180