Preparing Watermark for incorporation to core component suite (RF-12563)

This issue was opened to track changes of Watermark component in order to incorporate it into core component suite.

I did following modifications:

* fully utilized CDK XML templates
* used UIOutput as base class instead of UIInput
* removed suffix attribute (now inputs are automatically determined)
* removed for attribute (unified usage through nesting into input components)
* removed support for non-JSF inputs