When adding an annotation the focus should be inside WYSIWYG by default

This screenshot shows how the legacy way to set the focus did not work anymore.
When trying to look for the input, the WYSIWYG editor is not loaded and this fails to focus anything.
The solution I went with is to change the CKEditor configuration.

AFAIU, we mostly care about CKEditor/Realtime (based on CKEditor) for WYSIWYG editors.
This small fix should solve the issue for both and I think it's enough to close this issue. I'll close the issue as soon as https://github.com/xwiki/xwiki-platform/pull/3694 is merged.
Feel free to reopen it later if we should make it work with additional editors.