Adds copy and rename ability for adapters to implement

[warmwaffles]

• Adds FileStore.copy/3.
• Adds FileStore.rename/3.
• Adds FileStore.CopyError
• Adds FileStore.RenameError
• Fixes missing options for write when using FileStore.Config.
• Improves typespecs for FileStore.Config compile time generated functions.

[warmwaffles]

Changed move/3 to be rename/3 to follow closer to File.rename/2 as suggested.