fix: improvements to the rocket

[Roelymole]

• Rewritten the velocity calculations to account for gravity, which resolves Rocket spins around after running out of fuel #419 (or at least the main problem) as the rockets will no longer float in the air and spin around for very long before exploding.
• Improve the random rotations when the rocket is in the LauchStage.FAILED state.
• Allow the roll of the rocket to be changed with the shift/crouch and space/jump keys.
  • Prevent the camera angle from moving down when pressing shift in the rocket.
• Adjust the position of the first person camera with the rotation of the rocket.
  • Change the yaw of the camera at the same rate as changing the yaw of the rocket.
  • Invert the controls when in first person mode to be more intuitive.
• Add fire to the explosion when the atmosphere is breathable and use the crash landing damage source for a custom death message.
• Fix issues with the rotations when the rocket is pointing downwards - I cannot figure out what is causing these issues when the rocket is pointing down, I have tried everything I can think of, so if anyone else can help me see what I am missing that would be great.
  • The player's rotations are out of sync with the rocket when changing the yaw.
  • The rocket's rotation is incorrect if the roll is non-zero.

Rocket_Gravity.mp4

[Roelymole]

The remaining tasks are not too urgent and I will deal with them eventually, but I have merged this PR now to make the rockets functional again.