fix: Various sample fixes and QoL improvements.

[Tod-Rive]

• Dynamically generate RenderTextures to ensure DX11 compatibility (RandomWriteable).
• ESC quits built apps (except for getting-started which uses the new menu).
• New Rive-based menu in getting-started.
• Textures properly inverted for OpenGL.
• OpenGL and DX11 builds work on Windows.
• Upgraded to Unity package 0.1.180. Known Issues:
• minions head tracking sample doe not render Rive texture properly in OpenGL on Windows in the Editor. Builds work fine. a662953

[HayesGordon]

Thanks for getting these in!