FACES-1993 prepend ids of PartialVisitContext(s) with portlet namespace

Could line 35 and 36 be simplified to `if (!id.startsWith(separator) && !id.startsWith(containerClientIdAndSeparator) {`?

Also I'm wondering if the `containerClientId` should be prepended even when the `id` begins with `seperatorChar`. Would that make sense? I know that technically if you prepend with a `seperatorChar` you are looking to start at the root. But in a portlet, isn't the root the `containerClientId`?