Support preservation of symlinks for non-windows systems when using cp

[cochaviz]

Support preservation of symlinks for non-windows systems when using cp

As introduced in #1078, symlinks are not preserved, but this also includes other attributes which might be relevant for forensics. This PR introduces, firstly, support for preserving symlinks specifically, but could also include other attributes such as owner, timestamp, etc.

Proposed Changes

We want to introduce the various flags and options that cp supports for preserving flags (which are weirdly numerous? https://www.man7.org/linux/man-pages/man1/cp.1.html):

       -d     same as --no-dereference --preserve=links

[...]

       -P, --no-dereference
              never follow symbolic links in SOURCE

[...]

       --preserve[=ATTR_LIST]
              preserve the specified attributes

This addition allows all the above variations, showing warnings when the included attribute is no supported:

target-fs <file> -P some-symlinked-file

Which preserves the links attribute. Here an example of an unsupported attribute:

$ target-fs <file> --preserve=owner some-symlinked-file
2026-03-19T15:58:17.468205Z [warning  ] <Target missing_symlink.zip>: Failed to find OS plugin, falling back to default [dissect.target.target]
2026-03-19T15:58:17.468448Z [warning  ] Unsupported --preserve attributes (will be ignored): owner [dissect.target.tools.fs]

Closes #1636.

Checklist

• PR Title is descriptive of the changes
• The description is descriptive of the changes
• Tests are included and pass
• Closes related issue number