Isolate script removes wrong entry from sys.path for embedded Python on Windows

[karthiknadig]

In some cases sys.path looks like this:

[
'C:\\opt\\ros\\noetic\\x64\\python38.zip',  // we remove this entry
'C:\\opt\\ros\\noetic\\x64', 
'C:\\Users\\Karthik Nadig\\AppData\\Roaming\\Python\\Python38\\site-packages', 
'C:\\opt\\ros\\noetic\\x64\\lib\\site-packages', 
'', 
'C:\\Users\\Karthik Nadig\\.vscode\\extensions\\ms-python.python-2020.8.109390\\pythonFiles',
'C:\\opt\\ros\\noetic\\x64\\lib\\site-packages\\win32', 
'C:\\opt\\ros\\noetic\\x64\\lib\\site-packages\\win32\\lib', 
'C:\\opt\\ros\\noetic\\x64\\lib\\site-packages\\Pythonwin'
]

After isolation it looks like this:

[
'c:\\Users\\Karthik Nadig\\.vscode\\extensions\\ms-python.python-2020.8.109390\\pythonFiles\\.does-not-exist',
'C:\\opt\\ros\\noetic\\x64', 
'C:\\Users\\Karthik Nadig\\AppData\\Roaming\\Python\\Python38\\site-packages', 
'C:\\opt\\ros\\noetic\\x64\\lib\\site-packages', 
'', 
'C:\\Users\\Karthik Nadig\\.vscode\\extensions\\ms-python.python-2020.8.109390\\pythonFiles', 
'C:\\opt\\ros\\noetic\\x64\\lib\\site-packages\\win32', 
'C:\\opt\\ros\\noetic\\x64\\lib\\site-packages\\win32\\lib', 
'C:\\opt\\ros\\noetic\\x64\\lib\\site-packages\\Pythonwin'
]

When really it should be:

[
'c:\\Users\\Karthik Nadig\\.vscode\\extensions\\ms-python.python-2020.8.109390\\pythonFiles\\.does-not-exist',
'C:\\opt\\ros\\noetic\\x64\\python38.zip',
'C:\\opt\\ros\\noetic\\x64', 
'C:\\Users\\Karthik Nadig\\AppData\\Roaming\\Python\\Python38\\site-packages', 
'C:\\opt\\ros\\noetic\\x64\\lib\\site-packages', 
'', 
'C:\\opt\\ros\\noetic\\x64\\lib\\site-packages\\win32', 
'C:\\opt\\ros\\noetic\\x64\\lib\\site-packages\\win32\\lib', 
'C:\\opt\\ros\\noetic\\x64\\lib\\site-packages\\Pythonwin'
]

[karthiknadig]

remove both these entries while isolating:

'', 

Also look for and remove the workspace path (which should be cwd).

[karthiknadig]

Related #11434