Add Python venv activation support for Windows and PowerShell (#17839)

Release Notes:

- Add Python venv activation support for Windows and PowerShell

Additional:

I discovered a related bug on my Windows system. When first opening the
project, it fails to detect the virtual environment folder `.venv`.
After expanding the .venv folder in the Project Panel, it then becomes
able to detect the virtual environment folder. However, I don't know how
to fix it.

assets/settings/default.json

@@ -710,7 +710,7 @@
         // to the current working directory. We recommend overriding this
         // in your project's settings, rather than globally.
         "directories": [".env", "env", ".venv", "venv"],
-        // Can also be `csh`, `fish`, and `nushell`
+        // Can also be `csh`, `fish`, `nushell` and `power_shell`
         "activate_script": "default"
       }
     },