Simplify Transform Implementation Where Possible

[ilexp]

Summary

The Transform component is by far the most used component in Duality. Handling as many of them as possible while keeping performance impacts low is a priority. However, Transform currently carries some potentially costly logic that is rarely used, like calculating and updating velocity values. Investigate whether they can be removed, benchmark the results and compare them to previous benchmarks.

Analysis

• Check if velocity calculations can be removed. Might actually work without too many drawbacks.
• Check if change event delivery can be removed. Maybe not though - this could actually be quite useful, and RigidBody relies on this.
• Investigate potential optimizations for non-moving Transform components, which are probably 90% of them.

[ilexp]

Progress

• Investigated velocity calculation removal and found that this isn't possible without drawbacks.
  • A very important distinction in transform changes is whether an object was moved or teleported there. This makes a difference for attached sounds and sound listeners, but there are probably other cases as well.
  • This distinction is completely lost when taking away velocity from Transform. So for now, it will need to stay.
• Found no optimizations for non-moving transforms so far, except introducing an explicit IsStatic flag / property, which requires and extended design and is sort of a different issue.

Closing this issue for now as there's nothing much left to do within its scope. Open a new one when there's a more concrete design on static transforms, or other transform optimizations.