refactor(processors): enhance transform_features method across multiple processors (#1849)

* refactor(processors): enhance transform_features method across multiple processors

- Updated the transform_features method in various processors to utilize a copy of the features dictionary, ensuring immutability of the original features.
- Added handling for new feature keys and removed obsolete ones in the MapTensorToDeltaActionDict, JointVelocityProcessor, and others.
- Improved readability and maintainability by following consistent patterns in feature transformation.

* refactor(processors): standardize action and observation keys in delta_action_processor and joint_observations_processor

- Updated action and observation keys to use constants for improved readability and maintainability.
- Refactored the transform_features method in multiple processors to ensure consistent handling of feature keys.
- Enhanced error handling by raising exceptions for missing required components in action and observation processing.
- Removed obsolete code and improved overall structure for better clarity.

* [pre-commit.ci] auto fixes from pre-commit.com hooks

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* refactor(processors): remove unused import in joint_observations_processor

* refactor(processors): simplify transform_features method in delta_action_processor

* refactor(processors): streamline transform_features method in ImageCropResizeProcessor

* refactor(processors): improve error handling and streamline transform_features method in phone_processor

- Raised a ValueError for missing position and rotation in action to enhance error handling.

* refactor(processors): enhance error handling in JointVelocityProcessor

- Added a ValueError raise for missing current joint positions in the observation method to improve error handling and ensure the integrity of the transform_features method.

* refactor(processors): simplify transform_features method in robot kinematic processors

* refactor(processors): standardize action keys in phone_processor

* fix(processor): RKP feature obs -> act

---------

Signed-off-by: Adil Zouitine <adilzouitinegm@gmail.com>
Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>
Co-authored-by: Steven Palma <steven.palma@huggingface.co>

src/lerobot/scripts/rl/gym_manipulator.py

@@ -459,7 +459,9 @@ def make_processors(
     if cfg.processor.inverse_kinematics is not None and kinematics_solver is not None:
         # Add EE bounds and safety processor
         inverse_kinematics_steps = [
-            MapTensorToDeltaActionDict(),
+            MapTensorToDeltaActionDict(
+                use_gripper=cfg.processor.gripper.use_gripper if cfg.processor.gripper is not None else False
+            ),
             MapDeltaActionToRobotAction(),
             EEReferenceAndDelta(
                 kinematics=kinematics_solver,