Maintain file directory structure in archive

Currently, if a file to be included in an archive is stored in a sub directory off its public:// or private:// schema, that directory structure is not maintained in the resulting zip archive. (Note that you can specify an optional sub directory under the "File directory" form input when editing a field of type File.) Instead, all selected files will be included in the root directory of the zip archive and filenames changed to prevent duplicates.

A desired feature is to preserve this subdirectory structure in the resulting archive.

I have created a patch to accomplish this.

This patch has two components:

1. New "Operation Settings" for the archive action: Add a field to "Maintain file directory structure". The default is unchecked, preserving the existing behavior by default.

2. Modified archive creation functionality to maintain the file directory structure based on the specified operation setting.