Move mdx import out of loader into compile

[shilman]

Issue: N/A

To simplify the vite implementation of MDX1 per storybookjs/storybook#20823

What Changed

How to test

See attached tests

Change Type

• maintenance
• documentation
• patch
• minor
• major

📦 Published PR as canary version: 0.0.5--canary.20.d7a3376.0

✨ Test out this PR locally via:

npm install @storybook/[email protected]
# or 
yarn add @storybook/[email protected]

Version

Published prerelease version: v1.0.0-next.1

Changelog

💥 Breaking Change

• Update to 7.0 / mdx2-csf structure #19 (@shilman)

🐛 Bug Fix

• Move mdx import out of loader into compile #20 (@shilman)
• ReDoS attack patch #17 (@iarmbears)

Authors: 2

• @iarmbears
• Michael Shilman (@shilman)

[IanVS]

This is technically a breaking-change, I think, but we're still in pre-releases for 1.0.0, so I think this is good to go. It will simplify usage of mdx1-csf for non-webpack builders.