WIP: use FileSystem for globbing

[ajafff]

Checklist

• Fixes: make globbing use FileSystem abstraction #414
• Added or updated tests / baselines
• Documentation update

Overview of change

TODO:

• add tests for new CachedFileSystem#isSymbolicLink
• fine-tune MemoryFileSystem
  • make it work with symlinks linking to non-existent files
  • allow modifications and inspection of the final state
  • pass-through some real-existing folders and files (e.g. to resolve and require rules)
  • maybe replace with a combination of unionfs and memfs or memory-fs
• move to separate package
  • rework GlobFileSystem API
  • add tests for different glob options, ideally use glob's test cases

[ajafff]

Ref: isaacs/node-glob#280