test(web-app): add e2e fetch process

It tests the normal request case of timeserie

web-app/cypress/fixtures/example.json

@@ -0,0 +1,5 @@
+{
+  "name": "Using fixtures to represent data",
+  "email": "hello@cypress.io",
+  "body": "Fixtures are a great way to mock data for responses to routes"
+}