feat(CI): add 'start-app' job that checks whether an app's server starts up correctly

gitlab-ci/start-app.yml

+start-app:
+  image: registry.brickblock.sh/devops/docker/build:latest
+  stage: test
+  extends:
+    - .except-ci-release
+    - .cache-pull-only
+    - .skip-artifacts
+  interruptible: true
+  script:
+    - yarn test:e2e:dev
+    - yarn test:e2e:prod