Service to return items and controller to fetch all of them

Also includes some rearrangement within the test server - splitting the votes and syllabus item components into separate example pages.
Include 5 levels of topics and show next select function
Set mesh_headings_id hidden input value on select changes
Remove spec runner as it can be generated
Use shorthand array creation for levels
Remove unused promise in test and use while loop for levels

Thanks for the review @iHiD
Merge pull request #18 from meducation/syllabus-items

Syllabus items