* [Enhance] Support non-scalar type metric value.

* Refactor support.

* Fix non-scalar tags problem during validation

* Update tag processor.

* [Refactor]: modify interface of Visualizer.add_datasample (#365)

* [Refactor] Refactor data flow: refine `data_preprocessor`. (#359)

* refine data_preprocessor

* remove unused BATCH_DATA alias

* Fix type hints

* rename move_data to cast_data

* [Refactor] Refactor data flow: collate data in `collate_fn` of `DataLoader`  (#323)

* acollate data in dataloader

* fix docstring

* refine comment

* fix as comment

* refactor default collate and psedo collate

* foramt test file

* fix docstring

* fix as comment

* rename elem to data_item

* minor fix

* fix as comment

* [Refactor] Refactor data flow: `data_batch` argument of `Evaluator.process is a `dict` (#360)

* refine evaluator and metric

* compatible with new default collate

* replace default collate with pseudo

* Handle data_batch in metric

* fix unit test

* fix unit test

* fix unit test

* minor refine

* make data_batch optional

make data_batch optional

* rename outputs to predictions

* fix ut

* rename predictions to outputs

* fix docstring

* fix docstring

* fix unit test

* make outputs and data_batch to kwargs

* fix unit test

* keep signature of metric

* fix ut

* rename pred_sample arguments to data_sample(Visualizer)

* fix loop and ut

* [refactor]: Refactor model dataflow (#398)

* [Refactor] Refactor data flow: refine `data_preprocessor`. (#359)

* refine data_preprocessor

* remove unused BATCH_DATA alias

* Fix type hints

* rename move_data to cast_data

* refactor model data flow

tmp_commt

tmp commit

* make val_cfg and test_cfg optional

* roll back runner

* pass test mmdet

* fix as comment

fix as comment

fix ci in DataPreprocessor

* fix ut

* fix ut

* fix rebase main

* [Fix]: Fix test val ddp (#462)

* [Fix] Fix docstring and type hint of data flow (#463)

* Fix docstring of data flow

* change signature of hook

* fix unit test

* resolve conflicts

* fix lint

* [Refactor] Refactor the import rule

* minor refinement

* add a comment

* Move the design of hook to design/hook.md

* add relative links in docs

* update docstring of hooks

* refine checkpointhook docs

* refine

* fix comments

* refine

* add logging.md link in hook.md

* resolve comments

* fix typo

* support training with data without metainfo

* clean the code

* clean the code

* Fix resume message hub and save metainfo in messagehub

* fix as comment

* fix build train_loop during test

* fix build train_loop during test

* fix build train_loop during test

* fix build train_loop during test

* Fix as comment

* add base model, ddp model and unit test

* add unit test

* fix unit test

* fix docstring

* fix cpu unit test

* refine base data preprocessor

* refine base data preprocessor

* refine interface of ddp module

* remove optimizer hook

* add forward

* fix as comment

* fix unit test

* fix as comment

* fix build optimizer wrapper

* rebase main and fix unit test

* stack_batch support stacking ndim tensor, add docstring for merge dict

* fix lint

* fix test loop

* make precision_context effective to data_preprocessor

* fix as comment

* fix as comment

* refine docstring

* change collate_data output typehints

* rename to_rgb to bgr_to_rgb and rgb_to_bgr

* support build basemodel with built DataPreprocessor

* fix as comment

* fix docstring

* Support multiple optimizers

* minor refinement

* improve unit tests

* minor fix

* Update unit tests for resuming or saving ckpt for multiple optimizers

* refine docstring

* refine docstring

* fix typo

* update docstring

* refactor the logic to build multiple optimizers

* resolve comments

* ParamSchedulers spports multiple optimizers

* add optimizer_wrapper

* fix comment and docstirng

* fix unit test

* add unit test

* refine docstring

* RuntimeInfoHook supports printing multi learning rates

* resolve comments

* add optimizer_wrapper

* fix mypy

* fix lint

* fix OptimizerWrapperDict docstring and add unit test

* rename OptimizerWrapper to OptimWrapper, OptimWrapperDict inherit OptimWrapper, and fix as comment

* Fix AmpOptimizerWrapper

* rename build_optmizer_wrapper to build_optim_wrapper

* refine optimizer wrapper

* fix AmpOptimWrapper.step, docstring

* resolve confict

* rename DefaultOptimConstructor

* fix as comment

* rename clig grad auguments

* refactor optim_wrapper config

* fix docstring of DefaultOptimWrapperConstructor

fix docstring of DefaultOptimWrapperConstructor

* add get_lr method to OptimWrapper and OptimWrapperDict

* skip some amp unit test

* fix unit test

* fix get_lr, get_momentum docstring

* refactor get_lr, get_momentum, fix as comment

* fix error message

Co-authored-by: zhouzaida <zhouzaida@163.com>

* Support multiple optimizers

* minor refinement

* improve unit tests

* minor fix

* Update unit tests for resuming or saving ckpt for multiple optimizers

* refine docstring

* refine docstring

* fix typo

* update docstring

* refactor the logic to build multiple optimizers

* resolve comments

* ParamSchedulers spports multiple optimizers

* refine docstring

* RuntimeInfoHook supports printing multi learning rates

* resolve comments

* fix typo

* [Enhance] Add RuntimeInfoHook to update runtime information.

* move lr to runtime info

* docstring

* resolve comments

* update ut and doc