feat: Add API key authentication (#1254)

Closes #945

server/api/policies/is-authenticated.js

@@ -5,6 +5,7 @@
 
 module.exports = async function isAuthenticated(req, res, proceed) {
   if (!req.currentUser) {
+    // TODO: provide separate error for API keys?
     return res.unauthorized('Access token is missing, invalid or expired');
   }