Matomo 4 first beta release #16165

• [x] Publish blog post for developers to update their plugin (post is prepared and only needs to be published)
• [x] Email developers about making plugin compatible
• [x] Make tests work for our plugins
• [x] Release new plugin versions on the Marketplace
• [x] Use Matomo 4 on demo2
• [x] Publish new matomo name on packagist https://github.com/matomo-org/matomo/pull/16205#issuecomment-658003009 (ignored for now... we'll do this soon)
• [x] test actual updates from 3.14 and one older
• [x] document new profilable segment
• [x] reorganise updates to be faster
• [x] document view access widget token
• [x] have https://github.com/matomo-org/matomo-package/pull/112 merged

@sgiehl fyi I looked over all plugins and updated them to use the new PHP DI config format. Hoping I didn't miss anything. I used this command grep ^ plugins/*/config/*.php to look over all files. Maybe when you find time you can also have another quick look if you spot anything