E2E tests apps

[nicotsx]

As the number of apps in the app store grew to such a size, it has become increasingly challenging to manage updates and ensure quality within our app catalog. In order to mitigate as much as possible this issue we need to introduce E2E tests for apps.

1. Each app needs a proper docker healthcheck
2. Each app has a tests folder containing the body payload to run the install via API
3. When a PR gets opened a CI will run a Runtipi instance, call the install-app API with the pre-defined body and wait for the app to be in healthy state
4. If after x time it is not healthy, the CI will fail