chore(processor): add type alias RobotProcessorPipeline and PolicyProcessorPipeline (#1859)

* feat(processor): introduce PolicyProcessorPipeline and RobotProcessorPipeline as type aliases for DataProcessorPipeline

- Added PolicyProcessorPipeline and RobotProcessorPipeline type aliases to enhance clarity and maintainability in the processor module.
- Updated the __all__ list to include the new pipelines for better module export consistency.

* refactor(processor): replace DataProcessorPipeline with PolicyProcessorPipeline across multiple modules

- Updated all instances of DataProcessorPipeline to PolicyProcessorPipeline in various processor files for consistency and clarity.
- Adjusted function signatures to reflect the new pipeline type, enhancing maintainability and readability.

* refactor(processor): update hotswap_stats function to use PolicyProcessorPipeline

- Changed the parameter name from robot_processor to policy_processor for clarity.
- Ensured consistency with recent updates to the processor module by reflecting the new pipeline type in the function signature.

* refactor(processor): replace DataProcessorPipeline with PolicyProcessorPipeline in migrate_policy_normalization.py

- Updated the preprocessor and postprocessor to use PolicyProcessorPipeline for consistency with recent changes in the processor module.
- Enhanced clarity and maintainability by aligning with the new pipeline structure.

* refactor(processor): update hotswap_stats to use PolicyProcessorPipeline

- Changed the parameter type in hotswap_stats from DataProcessorPipeline to PolicyProcessorPipeline for consistency with recent updates.
- Enhanced clarity by updating the function documentation to reflect the new pipeline type.

* refactor(processor): replace DataProcessorPipeline with RobotProcessorPipeline across multiple files

- Updated instances of DataProcessorPipeline to RobotProcessorPipeline in evaluate.py, record.py, replay.py, teleoperate.py, and other relevant files for consistency and clarity.
- Adjusted function signatures and variable types to reflect the new pipeline structure, enhancing maintainability and readability.

src/lerobot/processor/__init__.py

@@ -46,10 +46,12 @@ from .pipeline import (
     IdentityProcessorStep,
     InfoProcessorStep,
     ObservationProcessorStep,
+    PolicyProcessorPipeline,
     ProcessorKwargs,
     ProcessorStep,
     ProcessorStepRegistry,
     RewardProcessorStep,
+    RobotProcessorPipeline,
     TruncatedProcessorStep,
 )
 from .rename_processor import RenameProcessorStep
@@ -79,6 +81,7 @@ __all__ = [
     "NormalizerProcessorStep",
     "Numpy2TorchActionProcessorStep",
     "ObservationProcessorStep",
+    "PolicyProcessorPipeline",
     "ProcessorKwargs",
     "ProcessorStep",
     "ProcessorStepRegistry",
@@ -88,6 +91,7 @@ __all__ = [
     "DataProcessorPipeline",
     "TimeLimitProcessorStep",
     "AddBatchDimensionProcessorStep",
+    "RobotProcessorPipeline",
     "TokenizerProcessorStep",
     "Torch2NumpyActionProcessorStep",
     "transition_to_batch",