Extend capsule flatpak endpint parametrization

[vsedmik]

Problem Statement

We are extending the Capsule Flatpak endpoint by the one filtered by Katello. We already have a test for the pulpcore endpoint, now the time has come to extend it for the newly added endpoint too.

Solution

This PR parametrizes the test to check both endpoints.
Another test case will be added for the CV/LCE filtering on the new endpoint once it's implemented.

Requires

Katello/smart_proxy_container_gateway#54
theforeman/puppet-foreman_proxy_content#522

Related Issues

https://issues.redhat.com/browse/SAT-30899

PRT test Cases example

We are not able to use packit/PRT since the patch needs to be applied on the Capsule side.
However, locally it passed:

$ pytest tests/foreman/api/test_capsulecontent.py -k test_flatpak_endpoint
========================== test session starts ==========================
collected 31 items / 29 deselected / 2 selected

tests/foreman/api/test_capsulecontent.py ..                       [100%]

============= 2 passed, 29 deselected, 5 warnings in 42.68s =============

[LadislavVasina1]

ACK

[vsedmik]

trigger: test-robottelo
pytest: tests/foreman/api/test_capsulecontent.py -k test_flatpak_endpoint

[Satellite-QE]

PRT Result

Build Number: 12087
Build Status: SUCCESS
PRT Comment: pytest tests/foreman/api/test_capsulecontent.py -k test_flatpak_endpoint --external-logging
Test Result: ========== 1 passed, 29 deselected, 9 warnings in 1521.09s (0:25:21) ===========