bug: fix removal of the packages

It has been broken since reporter improvements, because it effectivelly
1) didn't call remove functions in database
2) used empty repository identifier for web service

With those changes it also raises exception when you try to call id on
empty identifier

tests/ahriman/models/test_repository_id.py

@@ -7,10 +7,17 @@ def test_id() -> None:
     """
     must correctly generate id
     """
-    assert RepositoryId("", "").id == ""
     assert RepositoryId("arch", "repo").id == "arch-repo"
 
 
+def test_id_empty() -> None:
+    """
+    must raise exception on empty identifier
+    """
+    with pytest.raises(ValueError):
+        assert RepositoryId("", "").id
+
+
 def test_is_empty() -> None:
     """
     must check if repository id is empty or not