Improve creation and deletion of pagedesigner elements

Problem/Motivation

Pagedesigner usage on website for content creation ends up in large amount of pagedesigner elements created.
After a quick analysis, the following behaviour are causing issues:

• Mutliple pagedesigner container elements created for one node creation. This is due to pagedesigner_yoast form widget called on the add node form before the real container is actually created
• Pagedesigner elements never get deleted on node deletion. This is due to the option $remove being always FALSE by default when calling clearPagedesigner. While keeping element in the database and mark them as deleted makes sense for element deletion/restoration and publish/unpublish state of the node, we should make sure the elements get deleted for good when the node itself is deleted.
• Pagedesigner content duplication: creation date should not be copied from source. Deleted elements should not be copied from source ?

Steps to reproduce

Proposed resolution

Remaining tasks

User interface changes

API changes

Data model changes