Implement a ZIPFileSystem to load archived mods

[EliteMasterEric]

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Add a new file system or extend the existing files system, to allow loading mods from ZIP files rather than folders. This is convenient in terms of easier installs for end users.

For development purposes, mods should still be accessible from a folder structure.

A ZIP should be able to contain a single mod or multiple mods. The latter is useful for modpacks.