How to centrally align oEmbeds (including in Gutenberg)

Probably one of my favourite features in WordPress is the oEmbed features. oEmbed is a technology that allows you easily embed content from other sites that use oEmbed technology. Content such as YouTube videos, Twitter Tweets or Spotify playlists can be easily embedding by just dropping a link onto a page, but with the ease of use with WordPress, it can be tricky to style these posts. One usual styling is by making sure the content is centrally aligned. This can be a bit tricky. Here is how you centrally align oEmbeds, including instructions in Gutenberg. How is a oEmbed structured?
oEmbeds are usually structured within an