Vendor configuration: move everything to a class?

[mauritskorse]

Currently the package has a config that defines the various vendors and how to handle the icons provided by that vendor. In addition a vendor class should be used to define specific callbacks. Hence the configuration is split between different files.
It could be an option to move all of the config of a vendor into a single vendor class to keep everything together.

I'd be happy to hear what you would prefer.

[mauritskorse]

For now we keep the split config.