chore: Refactoring event processors and service architecture (#2495)

server/queues/processors/emails.js

@@ -0,0 +1,14 @@
+// @flow
+import mailer, { type EmailSendOptions, type EmailTypes } from "../../mailer";
+
+type EmailEvent = {
+  type: EmailTypes,
+  opts: EmailSendOptions,
+};
+
+export default class EmailsProcessor {
+  async on(event: EmailEvent) {
+    // $FlowIssue flow rightly doesn't like dynaic values
+    await mailer[event.type](event.opts);
+  }
+}