refactor: split common/nixos.nix and -/home.nix

Split these big files into modular files that
are easier to share and read on their own.

profiles/common/home/eza.nix

@@ -0,0 +1,12 @@
+{ ... }:
+{
+  programs.eza = {
+    enable = true;
+    icons = true;
+    git = true;
+    extraOptions = [
+      "-l"
+      "--group-directories-first"
+    ];
+  };
+}