fix: symlink creation of per-user apps/icons folder

[mprasil]

Closes #362

The code relied on defaultUser attribute name in config.users.users to be the same as the username. This is not always the case as the username can be set by name attribute inside the user configuration

So for following user

users.users.foo.name = "bar";

the wsl.defaultUser = "foo" works, but the wsl.startMenuLaunchers = true won't work because it tries to find applications folder at /etc/profiles/per-user/foo/share rather than
/etc/profiles/per-user/bar/share that is actually created.

This PR uses the name attribute of that user instead which should fix the issue. (tested locally, it seems to be working correctly)

[terlar]

This looks good. I just tried to figure out why my icons were not working and just found the solution:

diff --git a/modules/wsl-distro.nix b/modules/wsl-distro.nix
index 50b81ea..39aae15 100644
--- a/modules/wsl-distro.nix
+++ b/modules/wsl-distro.nix
@@ -125,7 +125,7 @@ in

             if (( ''${#targets[@]} != 0 )); then
               mkdir -p "/usr/share/$x"
-              ${pkgs.rsync}/bin/rsync -ar --delete-after "''${targets[@]}" "/usr/share/$x"
+              ${pkgs.rsync}/bin/rsync -ar --copy-dirlinks --delete-after "''${targets[@]}" "/usr/share/$x"
             else
               rm -rf "/usr/share/$x"
             fi

Since the hicolor icons folder was a symlink in the derivation rsync couldn't merge the sources and hence just copied one of them. This change ensures it copies directory links instead to avoid such issues. Tested and working with icons for me now. I'll wait with PR until this is merged.

[SuperSandro2000]

I've created #381 with your suggestion