Add support for the `caseFold` configuration

[lvcabral]

Rationale

The core implements support for the caseFold configuration to allow case insensitive access to the folders and files, and the archives still not handling it.

API Proposal

handle the existing caseFold parameter in the Configuration

Additional context

Also, currently, if the caseFold: 'lower' is configured in core there is no way to access files or folders that are not named in lowercase using an Zip file system for instance, so the configuration is not compatible with archives

[james-pre]

Thanks for opening an issue, I'll take a look.

[lvcabral]

@james-pre I created a draft PR with the Zip implementation (that's what I'm using for testing).
#17