Add server file to route external queries

1. Takes POST data of one param (URL) at localhost/ve
2. Sends query to Zotero instance
3. Receives Zotero response body
4. Sends Zotero body in response

Currently contains some unused code (commented out).

Change-Id: If7b4fd7990dd1207d2a0ce0e247a49b0d926c347