NXP-15644: do not add null facelet handler
NXP-14230: check action property before widget one to include content after/before
NXP-15642: add id to the theme head tag
NXP-15402: display 'select all' action as button and remove checkbox
NXP-15645: simplify and fix elements to render on content view ajax actions
NXP-15412: fix broken logics on conversation, that should be filled only on the 'onclick' attribute