The inplace edit mode should support WYSIWYG editors that don't produce HTML

Currently, the inplace edit mode assumes that all WYSIWYG editors expect as input HTML and output HTML. This is not true for editors like BlockNote though, see XWIKI-23025, which produce a specific JSON syntax.

There are a few things to improve:

• stop hard-coding the syntax used to render the content for edit (annotated HTML currently); take it instead from the configured WYSIWYG editor
• stop injecting the rendered content in the DOM document, because it may not be HTML
• when saving the content, let the WYSIWYG editor manage the submitted content fields; depending on the editor output, the editor may use either the RequiresHTMLConversion or the new RequiresConversion parameter and the associated extra parameters.