Allow to parse inline editable macro parameters in html result

We introduced with XRENDERING-518 the capabality to allow inline editing of Macro content. We should be able to do the same for macro parameters: it is already supported by CKEditor, but we need to be able to parse the HTML returned by CKEditor in order to save an edited macro parameter.
We should use the same attribute as in CKEditor to identify a block content for a parameter: data-xwiki-parameter-name (see: https://github.com/xwiki-contrib/application-ckeditor/blob/master/plugins/src/main/resources/xwiki-macro/plugin.js#L37)