[Dev] Our Python code doesn't typecheck correctly

[orpuente-MS]

Describe the bug

A lot of our Python code have type checking errors when we set PyLance type checking mode to "standard".

To Reproduce

Steps to reproduce the behavior:

1. Set PyLance type checking mode to "standard"
2. Open one of our Python files such as source\pip\qsharp\_qsharp.py
3. You will see multiple warnings and errors coming from PyLance

Expected behavior

Our Python code should type check as much as possible.

#2884 is an example of a PR fixing one of these PyLance typing issues.

Screenshots