Fix icon paths resolving in merged configs

[viktor-yakubiv]

I am not sure it's handled correctly. Let's imagine, we have icons in 2 packages or 2 different directories. We want to resolve one list from the first directory and another one from the second directory. Is it handled like that before merging config objects?

Comes after #206 (comment)

[Joozty]

To add on top of it: f we want to having it we need to add support for array in icons field something like:

  icons: [
    {
        path: '/package1Root',
        files: ['icon.svg'],
    },
    {
        path: 'package2Root',
        files: [icon.svg],
    },
]

[viktor-yakubiv]

We could but I would rather opt-out of this. If the user wants to have icons from various directories, he/she should expand absolute paths manually. So, I would keep supporting only object: { files: array[string], path: string } or array[string]