fix(Users): Makes sure verifying emails triggers hooks and liveQuery (#3851)

* Use RestWrite when verifying emails so hooks are called (as master)

* Fixes tests for postgres

* nit

* Makes rest.update support a full where instead of objectId

* Use rest.update to guaranteed proper beforeSave and liveQuery calls

src/RestWrite.js

@@ -360,7 +360,8 @@ RestWrite.prototype.transformUser = function() {
     throw new Parse.Error(Parse.Error.OPERATION_FORBIDDEN, error);
   }
 
-  if (this.query) {
+  // Do not cleanup session if objectId is not set
+  if (this.query && this.objectId()) {
     // If we're updating a _User object, we need to clear out the cache for that user. Find all their
     // session tokens, and remove them from the cache.
     promise = new RestQuery(this.config, Auth.master(this.config), '_Session', {