Update lit-starter-ts to lit-next

* Upgrades the source to work with lit-next
* Aligns the linting and formatting rules/settings & ignores with the monorepo
* Upgrades to the same version of typescript and tsconfig settings as the monorepo
* Upgrades the test runner from karma to web-test-runner
* Upgrades the dev server from es-dev-server to @web/dev-server

src/test/my-element_test.ts

@@ -1,4 +1,5 @@
 import {MyElement} from '../my-element.js';
+
 import {fixture, html} from '@open-wc/testing';
 
 const assert = chai.assert;