chore: Move to Typescript (#2783)

This PR moves the entire project to Typescript. Due to the ~1000 ignores this will lead to a messy codebase for a while, but the churn is worth it – all of those ignore comments are places that were never type-safe previously.

closes #1282

server/migrations/20171019071915-user-avatar-url.js

@@ -1,12 +1,11 @@
 module.exports = {
   up: async (queryInterface, Sequelize) => {
-    await queryInterface.addColumn('users', 'avatarUrl', {
+    await queryInterface.addColumn("users", "avatarUrl", {
       type: Sequelize.TEXT,
       allowNull: true,
     });
   },
-
   down: async (queryInterface, Sequelize) => {
-    await queryInterface.removeColumn('users', 'avatarUrl');
+    await queryInterface.removeColumn("users", "avatarUrl");
   },
 };