[Bug] Storybook experimental features ignored in portable stories

[vanessayuenn]

In Storybook we normally use the featuresmain.js property to allow users to toggle between certain experimental features like experimentalRSC, however those are not taken into account in portable stories:

// .storybook/main.js
export default {
  features: {
    experimentalRSC: true,
  },
}

💡 Solutions/Action items:

• We can add support for these by parsing that property in main.js and injecting into a FEATURES object in globalThis during a test run (in a virtual set up file or the like)
• We can discourage ourselves to use the features property whenever possible, and use parameters instead. The experimentalRSC flag was actually moved into parameters.react.rsc and that is automatically handled in portable stories