Remove many functions in utils and migrate them to mmengine (#2217)

* Remove runner, parallel, engine and device

* fix format

* remove outdated docs

* migrate many functions to mmengine

* remove sync_bn.py

tests/test_utils/test_parrots_jit.py

 # Copyright (c) OpenMMLab. All rights reserved.
 import pytest
 import torch
+from mmengine.utils import TORCH_VERSION
 
 import mmcv
-from mmcv.utils import TORCH_VERSION
 
 pytest.skip('this test not ready now', allow_module_level=True)
 skip_no_parrots = pytest.mark.skipif(

tests/test_utils/test_timer.py

-# Copyright (c) OpenMMLab. All rights reserved.
-import time
-
-import pytest
-
-import mmcv
-
-
-def test_timer_init():
-    timer = mmcv.Timer(start=False)
-    assert not timer.is_running
-    timer.start()
-    assert timer.is_running
-    timer = mmcv.Timer()
-    assert timer.is_running
-
-
-def test_timer_run():
-    timer = mmcv.Timer()
-    time.sleep(1)
-    assert abs(timer.since_start() - 1) < 1e-2
-    time.sleep(1)
-    assert abs(timer.since_last_check() - 1) < 1e-2
-    assert abs(timer.since_start() - 2) < 1e-2
-    timer = mmcv.Timer(False)
-    with pytest.raises(mmcv.TimerError):
-        timer.since_start()
-    with pytest.raises(mmcv.TimerError):
-        timer.since_last_check()
-
-
-def test_timer_context(capsys):
-    with mmcv.Timer():
-        time.sleep(1)
-    out, _ = capsys.readouterr()
-    assert abs(float(out) - 1) < 1e-2
-    with mmcv.Timer(print_tmpl='time: {:.1f}s'):
-        time.sleep(1)
-    out, _ = capsys.readouterr()
-    assert out == 'time: 1.0s\n'