Resolve name to oid in argparse

ugit/base.py

@@ -96,9 +96,11 @@ def commit(message):
 
     return oid
 
+
 def create_tag(name, oid):
     data.update_ref(f"refs/tags/{name}", oid)
 
+
 def checkout(oid):
     commit = get_commit(oid)
     read_tree(commit.tree)
@@ -126,5 +128,9 @@ def get_commit(oid):
     return Commit(tree=tree, parent=parent, message=message)
 
 
+def get_oid(name):
+    return data.get_ref(name) or name
+
+
 def is_ignored(path):
     return ".ugit" in path.split("/")