test: Migration to jest (#935)

* jest initialised

* refactor: `connect()` and `openApp()`

* test: integrate to jest

* chore: renaming jests test commands

* chore: adding override rule for non `commands/serve` directories to skip jest rules

jest.setup.js

@@ -0,0 +1,2 @@
+import '@testing-library/jest-dom';
+import 'whatwg-fetch';