NXP-13234: fix javadoc according to changes for NXP-12950
NXP-13234: format, remove tabs
NXP-13234: fix translation of file removal confirm
NXP-13234: remove useless context keeper here (useful for files selection loss on inputList tag, so useless here) + replace rendered attribute by a c:if tag
NXP-13234: cleanup/format old code
NXP-13234: fix behaviour on removal of an item (last item was still shown and feedback messages not visible)
NXP-13234: avoid bad interactions between page scope and seam remoting requests: using a a4j:jsFunction method to trigger clear of uploaded file(s) fixes the issue