Return the group project configuration value.

This value (expected to be an array of strings) can be used to
link related projects.

Closes #186.

lib/www/server/lib/db/project/get.js

@@ -1,7 +1,7 @@
 const { setSurvey, pool } = require('../connection');
 
 async function get () {
-	const res = await pool.query("SELECT pid, name, schema FROM public.projects;");
+	const res = await pool.query("SELECT pid, name, schema, COALESCE(meta->'groups', '[]'::jsonb) AS groups FROM public.projects;");
 	return res.rows;
 }