Fix python UnicodeDecodeError on windows

[MisakaQwQ]

Type

• Bug fix (non-breaking change which fixes an issue): Fixes #
• New feature (non-breaking change which adds functionality). Resolves #
• Breaking change (fix or feature that would cause existing functionality to not work as expected) Resolves #

Motivation and Context

I've met the same issues report in #6273, #5803, while building from source.
After comparing the pybind.cp37-win_amd64.pyd in binary, I found that some symbols describing the directory structure in cpp/pybind/data/dataset.cpp may escape unproperly while building on windows in some cases.

Checklist:

• I have run python util/check_style.py --apply to apply Open3D code style
  to my code.
• This PR changes Open3D behavior or adds new functionality.
  • Both C++ (Doxygen) and Python (Sphinx / Google style) documentation is
    updated accordingly.
  • I have added or updated C++ and / or Python unit tests OR included test
    results (e.g. screenshots or numbers) here.
• I will follow up and update the code if CI fails.
• For fork PRs, I have selected Allow edits from maintainers.

Description

Replaces some symbols with some plain ASCII characters.
I've tested on my computer, and these changes resolve my problem.

Operating system: Windows 10 Build 19045
Python version: Python 3.7.9 (tags/v3.7.9:13c94747c7, Aug 17 2020, 18:58:18) [MSC v.1900 64 bit (AMD64)] on win32
System architecture: x64-based PC
Compiler version: Visual Studio 2019 v16.11.27 (MSVC v142, Windows 10 SDK 10.0.19041.0)

>>> help(o3d.data.RedwoodIndoorLivingRoom1)
Help on class RedwoodIndoorLivingRoom1 in module open3d.cpu.pybind.data:

class RedwoodIndoorLivingRoom1(DownloadDataset)
 |  RedwoodIndoorLivingRoom1 (Augmented ICL-NUIM Dataset)
 |  Data class for `RedwoodIndoorLivingRoom1`, containing dense point
 |  cloud, rgb sequence, clean depth sequence, noisy depth sequence, oni
 |  sequence, and ground-truth camera trajectory.
 |
 |  RedwoodIndoorLivingRoom1
 |  |-- colors
 |  |   |-- 00000.jpg
 |  |   |-- 00001.jpg
 |  |   |-- ...
 |  |   '-- 02869.jpg
 |  |-- depth
 |  |   |-- 00000.png
 |  |   |-- 00001.png
 |  |   |-- ...
 |  |   '-- 02869.png
 |  |-- depth_noisy
 |  |   |-- 00000.png
 |  |   |-- 00001.png
 |  |   |-- ...
 |  |   '-- 02869.png
 |  |-- dist-model.txt
 |  |-- livingroom1.oni
 |  |-- livingroom1-traj.txt
 |  '-- livingroom.ply
 |
-- More  --

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This change is 

[update-docs]

Thanks for submitting this pull request! The maintainers of this repository would appreciate if you could update the CHANGELOG.md based on your changes.

[ssheorey]

Thanks @MisakaQwQ for this update!