Differentiated between user packages and system packages

We usually can't uninstall system packages, so display them
differently

Also fixed some missing `global`s.

package_manager/utils.py

@@ -0,0 +1,15 @@
+from pathlib import Path
+
+def parse_repository_url(url: str) -> str:
+    """Sanitize repository url"""
+    from urllib.parse import urlsplit, urlunsplit
+    parsed_url = urlsplit(url)
+    new_path = parsed_url.path.rstrip("repo.json")
+    return urlunsplit((parsed_url.scheme, parsed_url.netloc, new_path, parsed_url.query, parsed_url.fragment))
+
+def add_repojson_to_url(url: str) -> str:
+    """Add repo.json to a url"""
+    from urllib.parse import urlsplit, urlunsplit
+    parsed_url = urlsplit(url)
+    new_path = str(Path(parsed_url.path) / "repo.json")
+    return urlunsplit((parsed_url.scheme, parsed_url.netloc, new_path, parsed_url.query, parsed_url.fragment))