New setting allowNodeEnv

[brillout]

Description

// vike.config.js

export default {
  allowNodeEnv: {
    dev: ['local', 'test'],
    prod: ['staging'. 'test']
  }
}

Adding test to both dev and prod means that the test value can always be set.

Related:

• Vike 0.4.161 process.env.NODE_ENV hard convention is problematic #1482
• Cannot upgrade Vike due to hard NODE_ENV failure #1526
• vite.config.js#base should start with '/', 'http://', or 'https://' (it is ./ instead) when using storybook #798 (comment)