Implement automated UI integration test for serverless-example with quarkus DevUI

Summary
Create a test that will build devUI, quarkus devUI extension and then launch the devUI with the example ad do some UI tests

GOAL
1. Build devUI
2. Build quarkus devUI extension -> snapshot
3. Checkout example
4. sed version of quarkus devUI to snapshot in the example
5. Run the example
6. Open the devUI console and execute UI tests
7. Validate expected workflow, starting workflows (from, noForm, cloudEvent)

AC
Tests are merged in the community