Draft: Take translations into account to find and replace searched text

WIP. Catching this up to the 2.0.x main branch (was 3 years stale)

What's left:

• When Drupal's $getQuery()->execute() runs, it return a list of entities that match on the text in ANY of the languages. Some logic here presupposes that there's a match in every language (leftover from when it wasn't away of multiple languages at all)
• Assess issues in Node::search()
• Assess issues in Paragraph::search()
• Assess issues in Node::replace()
• Assess issues in Paragraph::replace()
• Assess issues in Node::undo()
• Assess issues in Paragraph::undo()
• Add functional test for multilanguage Search (Node and Paragraph)
• Add functional test for multilanguage Replace (Node and Paragraph)
• Add functional test for multilanguage Undo (Node and Paragraph)