Adds ability to pause in gizmo examples

[kfc35]

Objective

• Fixes Make bevy gizmos examples pausable #22203

Solution

• Utilize the virtual clock to pause time! Use the real time clock in config as well, though, since increasing and decreasing line widths scales happens with elapsed time deltas.
• I did not include an indicator for when the scenes are paused / unpaused since it seems there is at least one thing constantly moving in the two scenes unless they are paused. (the 2d example has that constantly rotating oval, and the 3d example has that constantly moving grid gizmo in the air)

Testing

• Did you test these changes? If so, how?
  I ran both the affected examples:
  cargo run --example 3d_gizmos --features=“free_camera”
cargo run --example 2d_gizmos
  Pausing works as expected, and increasing/decreasing line widths while paused still works

[Hilpogar]

Tested and approved 👍