JBIDE-17849 CSS Hyperlinks aren't working on non-WTP projects

An utility helper method is added due to find pages in projects that are not the WTP ones
(has no web-roots that can be achieved by WTP methods)

Signed-off-by: vrubezhny <vrubezhny@exadel.com>
There should not be any null in this array. If it is then there is a bug in WebUtils.getWebContentPaths(project) method. We should not hide such problems using null checking.