Make device list of midi-input/-output available.

[NeoCortex97]

I think enabeling the midi-input and midi-output services to deliver a list of available devices would be beneficial since it would enable at least an easier configuration.

[hlxid]

This could also be relevant for Streamdeck.

A couple random ideas on how we could implement this:

1. An easy solution for this would to simply print a list of connected devices on startup.
2. A for sure better solution would be to have a dashboard panel for each service bundles which has a device list. This would also allow for updating as devices get connected or disconnected.
3. Allow for bundles to provide config templates from which a config can be created in the dashboard. So here the service could provide a config template for each connected device.
   Might also be good to have some templates for the other services so they can show how the config structured and show different options. E.g. for Philips Hue different templates could show how to use a provided address or how to use auto-discover.
   The user then only has to update the config with their credentials and don't necessarily need to check the documentation when creating a new service instance.