Control aloha robot natively (#316)

Co-authored-by: Simon Alibert <75076266+aliberts@users.noreply.github.com>

lerobot/common/robot_devices/robots/utils.py

@@ -1,6 +1,13 @@
 from typing import Protocol
 
 
+def get_arm_id(name, arm_type):
+    """Returns the string identifier of a robot arm. For instance, for a bimanual manipulator
+    like Aloha, it could be left_follower, right_follower, left_leader, or right_leader.
+    """
+    return f"{name}_{arm_type}"
+
+
 class Robot(Protocol):
     def init_teleop(self): ...
     def run_calibration(self): ...