Remove python stubs directory (#4955)

* Remove python stubs directory

- Removing python stubs directory since after https://github.com/QuantConnect/Lean/pull/4899
it was been replaced by a python package `quantconnect-stubs`.
- Reverting IDE settings using the stubs folder PR https://github.com/QuantConnect/Lean/pull/4657

* Revert "Adds Python stubs location definition for PyCharm and Visual Studio Code (#4657)"

This reverts commit aded66ec5b.

* Address self-review: Provide list of imports and refactor python readme

Co-authored-by: Gerardo Salazar <gsalaz9800@gmail.com>

Algorithm.Python/QuantConnect.Algorithm.PythonTools.pyproj

@@ -6,7 +6,8 @@
     <ProjectHome>.</ProjectHome>
     <StartupFile>
     </StartupFile>
-    <SearchPath>stubs</SearchPath>
+    <SearchPath>
+    </SearchPath>
     <WorkingDirectory>.</WorkingDirectory>
     <OutputPath>.</OutputPath>
     <Name>QuantConnect.Algorithm.PythonTools</Name>