Addon-docs: Vue slots/events props table + generalization

[shilman]

Issue: #8123

What I did

• Props: Added sections prop for Vue/Angular etc (events/slots/etc.)
• Left rows still back-compat for React (no sections needed)
• Split react/vue props extraction & made it preset-configurable
• Left props extract inference for React/Vue for back-compat
• Cleaned up examples from Addon-docs: Fix React.forwardedRef/memo props #8445
• Cleaned up DocgenButton from official-storybook as named export

What I need

• Review Vue example ported from vue-addon-info - do we need more? @Aaron-Pool
• PropsTable styling @domyen

How to test

React:

cd examples/official-storybook
yarn storybook

Vue:

cd ../vue-kitchen-sink
yarn storybook

[vercel]

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[Aaron-Pool]

@shilman how would you like me to contribute examples? Actually pull this branch down, or just send you some code snippets directly?

[Aaron-Pool]

@shilman I switched the callback-props being used in the vue stories to use vue events, and properly notated them for the docgen-api, like we discussed earlier today 👍 I also removed those few remaining static heights being set on a few of the inline stories, which was causing overflow issues. This is starting to look pretty great, appreciate the hard work! 🔥🔥🔥