Channels that didn't depend on architecture

[rjmateus]

Setting up a minima mirror using sumaform.
We try to use a channel that didn't depend on the architecture. channel name: - SLE-15-GA-Desktop-NVIDIA-Driver resulting in the channel not been downloaded.

Filter tries to match the archs defined in minima.yaml to the arch to where the channel was defined.

Snippet from organization_repositories.json file:

    {
        "autorefresh": true,
        "description": "SLE-15-GA-Desktop-NVIDIA-Driver for ",
        "distro_target": null,
        "enabled": true,
        "id": 2747,
        "installer_updates": false,
        "name": "SLE-15-GA-Desktop-NVIDIA-Driver",
        "url": "https://download.nvidia.com/suse/sle15/"
    },

We should define a rule to handle this type of channels and allow download arch independent channels.