JBIDE-16687 provide access to palette entries via content assist
JBIDE-16687 provide access to palette entries via content assist

JUnit test is added for the issue: org.jboss.tools.jst.web.ui.editor.test.ca.JstCAJQMFromPaletteTest

Signed-off-by: vrubezhny <vrubezhny@exadel.com>