15.0.0-alpha.4

Breaking

• Markup change in LinkView component.
• Rename core-sandbox to coresandbox for sake of consistency @sneridagh
• Extend the original intent and rename RAZZLE_TESTING_ADDONS to ADDONS. @sneridagh
  See https://docs.voltocms.com/upgrade-guide/ for more information.

Internal

• House cleanup, remove some unused files in the root @sneridagh
• Move Webpack related files to webpack-plugins folder @sneridagh
• Remove unused Dockerfiles @sneridagh
• Update Docker compose to latest images and best practices @sneridagh