img/vid: Inline CSS property aspect-ratio to prevent Cumulative Layout Shift and improve Web Vitals

[aia]

• Why and How: https://web.dev/aspect-ratio/#example-preventing-layout-shift
• MDN Docs: https://developer.mozilla.org/en-US/docs/Web/CSS/aspect-ratio
• Works everywhere: https://caniuse.com/?search=aspect-ratio

Edited October 9, 2022 by 13.