Decide how to test the Open Saas template

[sodic]

Strongly related to wasp-lang/wasp#3224.

We should decide how and what to test in the Open Saas template:

• Should we ever manually test the template (not OpenSaas.sh) or just leave it to the CI?
• If so, how and where?
• @FranjoMindek added that "to test it throughly you do need access to e.g. Stripe dashboard. So you need your own Stripe sandbox project."

[FranjoMindek]

Too add onto my quote:

I was referring to manually testing the saas starter template.
Especially when modifying any logic related to payment providers.

However all of the "dashboard" data can be accessed via API.