fs: pass symlink type in cp when filter is provided

[shulaoda]

When fs.cp/fs.cpSync is called with both verbatimSymlinks: true and a filter function, directory symlinks are incorrectly created as file symlinks on Windows.

Root cause

fs.cp takes two code paths:

• Without filter: the C++ fast path (cpSyncCopyDir) uses std::filesystem::copy_symlink() which preserves the symlink type automatically.
• With filter: the JS fallback path calls symlinkSync(resolvedSrc, dest) without a type parameter. On Windows, symlinkSync tries to auto-detect the type by stat-ing the resolved target at the destination. During a recursive copy, the target directory may not yet exist at the destination (e.g. linked/ is copied before packages/ in alphabetical order), so stat fails and type defaults to 'file' creating a file symlink instead of a directory symlink.

Fix

Detect the symlink type from the source (which always exists) using internalModuleStat(src) and pass it explicitly to symlinkSync/symlink. The onLink function already computed srcIsDir for subdirectory validation but only after the early-return paths this change moves it before those returns and threads the derived symlinkType through to all symlinkSync/symlink call sites.

Both the sync (cp-sync.js) and async (cp.js) implementations are fixed.

Test

Added two test files that verify directory symlinks are preserved when copying with verbatimSymlinks: true and a filter function:

• test-fs-cp-sync-verbatim-dir-symlinks-with-filter.mjs
• test-fs-cp-async-verbatim-dir-symlinks-with-filter.mjs

Fixes: #62653