win_exec: refactor PS exec runner (#45334)

* win_exec: refactor PS exec runner

* more changes for PSCore compatibility

* made some changes based on the recent review

* split up module exec scripts for smaller payload

* removed C# module support to focus on just error msg improvement

* cleaned up c# test classifier code

test/runner/lib/util.py

@@ -489,6 +489,7 @@ def is_binary_file(path):
         '.cfg',
         '.conf',
         '.crt',
+        '.cs',
         '.css',
         '.html',
         '.ini',