GNOME dependable installation, structure and style improvements

Split utils in utils.py to a directory
Moved ./gnome-shell_css/ to ./gnome-shell/.css/

scripts/utils/copy_files.py

@@ -0,0 +1,12 @@
+import os
+
+def copy_files(source, destination):
+    """
+    Copy files from the source to another directory
+    :param source: where files will be copied
+    :param destination: where files will be pasted
+    """
+
+    destination = os.path.expanduser(destination)  # expand ~ to /home/user
+    os.makedirs(destination, exist_ok=True)
+    os.system(f"cp -aT {source} {destination}")