[tests][m]: Setup Integration Tests with Cypress (#26).

* [cypress][s]-setup-integration=with-cypress
* [fix][s]- fix typescript bug 'All files must be modules when the '--isolatedModules' flag is provided' by adding an 'export {}' to all test files
* Fixes of cypress tests
* Use yarn everywhere not npm

Co-authored-by: Abhishek Gahlot <me@abhishek.it>

cypress.json

@@ -0,0 +1,3 @@
+{
+  "baseUrl": "http://localhost:3000"
+}