Remove deprecated MediaManager (#1262)

<!-- Contributing guide:
https://github.com/openvinotoolkit/datumaro/blob/develop/CONTRIBUTING.md
-->

### Summary
- Ticket no. 131646
- `MediaManager` looks deprecated because there is no usage (`.get()`)
in the codebase but only remains `.push()` and `.clear()`.
- However, this makes [weakref-related errors in OTX 2.0 integration
tests](https://github.com/openvinotoolkit/training_extensions/actions/runs/7665862410/job/20892722202?pr=2841).
Therefore, it seems good to remove.

### How to test
No need for the test

### Checklist
<!-- Put an 'x' in all the boxes that apply -->
- [x] I have added unit tests to cover my changes.​
- [x] I have added integration tests to cover my changes.​
- [x] I have added the description of my changes into
[CHANGELOG](https://github.com/openvinotoolkit/datumaro/blob/develop/CHANGELOG.md).​
- [x] I have updated the
[documentation](https://github.com/openvinotoolkit/datumaro/tree/develop/docs)
accordingly

### License

- [x] I submit _my code changes_ under the same [MIT
License](https://github.com/openvinotoolkit/datumaro/blob/develop/LICENSE)
that covers the project.
  Feel free to contact the maintainers if that's a concern.
- [x] I have updated the license header for each file (see an example
below).

```python
# Copyright (C) 2023 Intel Corporation
#
# SPDX-License-Identifier: MIT
```

---------

Signed-off-by: Kim, Vinnam <vinnam.kim@intel.com>

Author: vinnamkim

CHANGELOG.md

@@ -65,6 +65,8 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
   (<https://github.com/openvinotoolkit/datumaro/pull/1251>)
 - Add default value for target in prune cli
   (<https://github.com/openvinotoolkit/datumaro/pull/1253>)
+- Remove deprecated MediaManager
+  (<https://github.com/openvinotoolkit/datumaro/pull/1262>)
 
 ## Jan. 2024 Release 1.5.2
 ### Enhancements

src/datumaro/__init__.py

@@ -57,7 +57,6 @@
 from .components.importer import FailingImportErrorPolicy, Importer, ImportErrorPolicy
 from .components.launcher import Launcher
 from .components.media import Image, MediaElement, Video, VideoFrame
-from .components.media_manager import MediaManager
 from .components.progress_reporting import (
     NullProgressReporter,
     ProgressReporter,

src/datumaro/components/media.py

@@ -9,7 +9,6 @@
 import os
 import os.path as osp
 import shutil
-import weakref
 from copy import deepcopy
 from enum import IntEnum
 from typing import (
@@ -603,10 +602,6 @@ def __init__(
         self._frame_count = None
         self._length = None
 
-        from .media_manager import MediaManager
-
-        MediaManager.get_instance().push(weakref.ref(self), self)
-
     def close(self):
         self._iterator = None
 

src/datumaro/components/media_manager.py

@@ -72,7 +72,6 @@
     VcsError,
 )
 from datumaro.components.launcher import Launcher
-from datumaro.components.media_manager import MediaManager
 from datumaro.util import find, parse_json_file, parse_str_enum_value
 from datumaro.util.log_utils import catch_logs, logging_disabled
 from datumaro.util.os_util import (
@@ -1812,8 +1811,6 @@ def init(cls, path) -> Project:
         return project
 
     def close(self):
-        MediaManager.get_instance().clear()
-
         if self._dvc:
             self._dvc.close()
             self._dvc = None
@@ -2012,8 +2009,6 @@ def remove_cache_obj(self, ref: Union[Revision, ObjectId]):
         if self.readonly:
             raise ReadonlyProjectError()
 
-        MediaManager.get_instance().clear()
-
         obj_type, obj_hash = self._parse_ref(ref)
 
         if self._is_cached(obj_hash):
@@ -2364,8 +2359,6 @@ def remove_source(self, name: str, *, force: bool = False, keep_data: bool = Tru
         if name not in self.working_tree.sources and not force:
             raise UnknownSourceError(name)
 
-        MediaManager.get_instance().clear()
-
         self.working_tree.sources.remove(name)
 
         data_dir = self.source_data_dir(name)
@@ -2502,8 +2495,6 @@ def checkout(
 
         rev = rev or "HEAD"
 
-        MediaManager.get_instance().clear()
-
         if sources:
             rev_tree = self.get_rev(rev)
 
@@ -2714,8 +2705,6 @@ def remove_model(self, name: str):
         if name not in self.models:
             raise KeyError("Unknown model '%s'" % name)
 
-        MediaManager.get_instance().clear()
-
         self._config.models.remove(name)
 
         data_dir = self.model_data_dir(name)

src/datumaro/components/project.py

@@ -6,7 +6,6 @@
 import numpy as np
 import pytest
 
-from datumaro.components.media_manager import MediaManager
 from datumaro.util.scope import on_exit_do, scope_add, scoped
 
 from ...requirements import Requirements, mark_requirement
@@ -22,7 +21,6 @@ class VideoSplittingTest:
     @patch("datumaro.components.media.VideoFrame.data", new_callable=PropertyMock)
     def test_can_split_video(self, mock_video_frame_data):
         mock_video_frame_data.return_value = np.full((32, 32, 3), fill_value=0, dtype=np.uint8)
-        on_exit_do(MediaManager.get_instance().clear)
 
         test_dir = scope_add(TestDir())
         video_path = osp.join(test_dir, "video.avi")

tests/integration/cli/test_utils.py

@@ -13,7 +13,6 @@
 from datumaro.components.dataset import Dataset
 from datumaro.components.dataset_base import DatasetItem
 from datumaro.components.media import Image, Video, VideoFrame
-from datumaro.components.media_manager import MediaManager
 from datumaro.components.project import Project
 from datumaro.util.scope import Scope, on_exit_do, scope_add, scoped
 
@@ -122,8 +121,6 @@ class VideoExtractorTest:
     @mark_requirement(Requirements.DATUM_GENERAL_REQ)
     @scoped
     def test_can_read_frames(self, fxt_sample_video):
-        on_exit_do(MediaManager.get_instance().clear)
-
         expected = Dataset.from_iterable(
             [
                 DatasetItem(
@@ -145,7 +142,6 @@ def test_can_read_frames(self, fxt_sample_video):
     @scoped
     def test_can_split_and_load(self, fxt_sample_video):
         test_dir = scope_add(TestDir())
-        on_exit_do(MediaManager.get_instance().clear)
 
         expected = Dataset.from_iterable(
             [