Regression test for all three hello-world demos

[hanxiao]

Describe the feature

hello-world examples are important, if it breaks for a first-time user, then we lose this user.

The current tests on hello-world is not enough, it does not check (1) if index/search is successful (2) the sanity of retrieved results.

Your proposal

Please add regression test for three hello-world.

---

Environment

Screenshots

Tasks:

• helloworld
• multimodal
• chatbot
• ci/cd pipeline

[JoanFM]

Example for multimodal can be taken from reverted change in #2178. It was reverted for other reasons, but the test would still be valid

[bwanglzu]

glad to work on it with other engineers.

[JoanFM]

Multimodal helloworld has already been added, please add the other integration tests in the same subfolders

[JoanFM]

One thing to be aware of.

Adding these tests, make the tests dependant on the hub submodule, which will bring to a situation where the tests in core do not pass because the hub needs an update and the hub will not be updatable because the new core version is not released

[JoanFM]

@bwanglzu can u make sure the helloworld examples tests are moved to their own folder independent of integration tests? Like this we can easily skip it when necessary much easier

[bwanglzu]

@JoanFM I will