add info to workaround issue#981

[fsb4000]

issue #981

I think that this information will be useful until the python test scripts are rewritten so that they can work with any active codepage.

If you have a better wording for this item then let me know.

[fsb4000]

python 3.9.5 broke the workaround :(

[fsb4000]

Changing Windows 10 user inteface to English helped with python 3.9.5. Tests passes...

[fsb4000]

I found an another method.
If you have Visual Studio installed with only English language pack then tests passes without any manipulations with chcp or changing Windows user interface language.
(Previously I had 2 language packs installed: Russian and English)

[cpplearner]

Can we either fix the compiler warnings or change the script to decode the output with the current console code page (e.g. change out = out.decode() to something like out = out.decode(encoding=f"cp{__import__('ctypes').cdll.kernel32.GetConsoleOutputCP()}"))?

[fsb4000]

I experimented a little and realized that it was enough to change these settings
Settings and then: All Settings -> Time & Language -> Language -> "Administrative Language Settings" -> "Administrative" -> "Change system locale"
to English.
Windows 10 user inteface remains in the local language.

So currently 2 working solutions:

1. Visual Studio installed with only English language pack

or

2. Change Settings and then: All Settings -> Time & Language -> Language -> "Administrative Language Settings" -> "Administrative" -> "Change system locale" to English.

But I think @cpplearner is right. We should fix it in the python scripts.
So I'm going to close this PR.
If someone will have a problem with the tests, then we can suggest these 2 solutions.