CreateAction should preserve any existing URL query string

It seems that CreateAction.java filters out all URL parameters except the ones named "template", "parent" or "title". This prevents the use case where additional parameters are provided to work, typically for performing a consecutive action via a redirect. This issue is about keeping the provided parameters as is in the URL when doing a create action, unless this raises security concerns. What do you think about this improvement idea?

Winking at caubin