Updating code_utils.py to solve issue #1747 (#1758)

* Update code_utils.py

Updated the powershell command to pwsh

* Update code_utils.py

added a split to handle powershell in the first condition as well

* Update local_commandline_code_executor.py

added "pwsh" as a command option in lang variable

* Update autogen/coding/local_commandline_code_executor.py

Co-authored-by: Eric Zhu <ekzhu@users.noreply.github.com>

* Update code_utils.py

* Update code_utils.py

fixed formatting

* Update code_utils.py

defined a function to detect whether 'powershell' or 'pwsh' works and accordingly use the one that works

* Update code_utils.py

fixed formatting

* Update and rename test_code.py to test_code_utils.py

added a unit test for get_powershell_command function in code_utils.py

* Update test_code_utils.py

fixed formatting

* Update test_code_utils.py

fixed formatting

* Update autogen/code_utils.py

Co-authored-by: Chi Wang <wang.chi@microsoft.com>

* solved issue #1747

* updated unit test

* fixed formatting

* fixed formatting

* fixed formatting

* fixed a bug

* removed extra return None and removed redundant comments

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Co-authored-by: Eric Zhu <ekzhu@users.noreply.github.com>
Co-authored-by: Chi Wang <wang.chi@microsoft.com>