Fix media contents error in arrow format

[cih9088]

Summary

• Fixed to initialize Image media from bytes not a decoded numpy array
• Fixed not to save PointCloud when save_media=False

How to test

Checklist

• I have added unit tests to cover my changes.​
• I have added integration tests to cover my changes.​
• I have added the description of my changes into CHANGELOG.​
• I have updated the documentation accordingly

License

• I submit my code changes under the same MIT License that covers the project.
  Feel free to contact the maintainers if that's a concern.
• I have updated the license header for each file (see an example below).

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

Signed-off-by: Inhyuk Andy Cho andy.inhyuk.jo@intel.com

[codecov-commenter]

Codecov Report

Patch coverage: 100.00% and project coverage change: -0.03 ⚠️

Comparison is base (320ea82) 78.70% compared to head (64aa4b2) 78.67%.

Additional details and impacted files

@@                Coverage Diff                 @@
##           releases/1.2.0     #986      +/-   ##
==================================================
- Coverage           78.70%   78.67%   -0.03%     
==================================================
  Files                 231      231              
  Lines               26425    26421       -4     
  Branches             5260     5263       +3     
==================================================
- Hits                20797    20787      -10     
- Misses               4401     4408       +7     
+ Partials             1227     1226       -1     

Flag	Coverage Δ
macos-11_Python-3.8	77.69% <100.00%> (-0.03%)	⬇️
ubuntu-20.04_Python-3.8	78.64% <100.00%> (-0.03%)	⬇️
windows-2019_Python-3.8	78.55% <100.00%> (-0.03%)	⬇️

Flags with carried forward coverage won't be shown. Click here to find out more.

Impacted Files	Coverage Δ
datumaro/components/media.py	79.01% <100.00%> (-0.07%)	⬇️
...atumaro/plugins/data_formats/arrow/mapper/media.py	73.79% <100.00%> (-2.25%)	⬇️

... and 1 file with indirect coverage changes

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[vinnamkim]

Would you change the target branch of this PR to releases/1.2.0?

[vinnamkim]

LGTM.