Projects natures and names cleanup

Maven matures were removed from plug-in projects
Java natures were removed from feature projects
Site project name changed to have jst module prefix
JBIDE-17850 Ionic palette: New Scroll wizard

New Scroll wizard is implemented.
New Content wizard is implemented.
Tests are added.
JBIDE-17726 Wierd proposals in css content assist for ionic projects

CSS Proposals are fixed
NPE in CSS Hyperlink is fixed
JUnit Test Case is added

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