Merge tag '2.0-beta2' into develop

Version 2.0-beta2
Remove page component specific translations.
Finally remove the old, obsolete codebase from the repository.
Make the menu and template select field mandatory.
Add translations for the content element.
Extract the page id condition into page component.
Only deep describe collapsed conditions.
Add type doc.
Add select-element navigation template.
Make the templates spaceless.
Update composer.lock.
Require contao/core >=3.2.1,<4-dev now.
Merge branch 'release/2.0.0-beta3'