Add rendering loop to experimental

[JasonGrace2282]

Adds in the rendering loop. TL;DR, the following now works

class Demo(Scene):
    def construct(self):
        self.play(DrawBorderThenFill(ManimBanner()))

The camera and interactivity still need to be added

Breaking Changes

• OpenGLCameraFrame was renamed to Camera
• Cairo renderer and Cairo Camera were deleted (they can be restored if need be)
• Separate :class:.Animation and :class:.Scene #3695 Changes

Completed

• Added a RenderManager
• Separate Animation from Scene
• Get the "typical manim" render loop going

TBD

These are TODOs for Experimental, not neccessarily for this PR

• Optimization Galore
  • Rewrite Bézier curves (Mobject.points) to be relative to center of Mobject
• Rebase with main (likely after this PR is merged)
• Yank out Cairo Mobjects
• Make RenderManager manage Scene and Window instead of Scene managing RenderManager and Window