refactor(pipeline): feature contract now categorizes between OBS or Action (#1867)

* refactor(processor): signature of transform_features

* refactor(processor): remove prefixes + processor respect new transform_features signature + update test accordingly

* refactor(processor): rename now is only for visual

* refactor(processor): update normalize processor

* refactor(processor): update vanilla processor features

* refactor(processor): feature contract now uses its own enum

* chore(processor): rename renameprocessor

* chore(processor): minor changes

* refactor(processor): add create & change aggregate

* refactor(processor): update aggregate

* refactor(processor): simplify to functions, fix features contracts and rename function

* test(processor): remove to converter tests as now they are very simple

* chore(docs): recover docs joint observations processor

* fix(processor): update RKP

* fix(tests): recv diff test_pipeline

* chore(tests): add docs to test

* chore(processor): leave obs language constant untouched

* fix(processor): correct new shape of feature in crop image processor

examples/phone_to_so100/replay.py

@@ -20,7 +20,7 @@ import time
 from lerobot.datasets.lerobot_dataset import LeRobotDataset
 from lerobot.model.kinematics import RobotKinematics
 from lerobot.processor import RobotProcessorPipeline
-from lerobot.processor.converters import action_to_transition, transition_to_robot_action
+from lerobot.processor.converters import action_to_transition, transition_to_action
 from lerobot.robots.so100_follower.config_so100_follower import SO100FollowerConfig
 from lerobot.robots.so100_follower.robot_kinematic_processor import (
     AddRobotObservationAsComplimentaryData,
@@ -60,7 +60,7 @@ robot_ee_to_joints_processor = RobotProcessorPipeline(
         ),
     ],
     to_transition=action_to_transition,
-    to_output=transition_to_robot_action,
+    to_output=transition_to_action,
 )
 
 robot_ee_to_joints_processor.reset()