Refactoring typing_inspect.py

[hallvictoria]

Description

Previously, typing_inspect.py had a distinction between python versions <3.7 and >=3.7, and would change imports and return statements based on the python version. This refactoring changes this so that there are no longer special cases for python versions <3.7.

Fixes # https://github.com/Azure/azure-functions-pyfx-planning/issues/177

---

PR information

• The title of the PR is clear and informative.
• There are a small number of commits, each of which has an informative message. This means that previously merged commits do not appear in the history of the PR. For information on cleaning up the commits in your pull request, see this page.
• If applicable, the PR references the bug/issue that it fixes in the description.
• New Unit tests were added for the changes made and CI is passing.

Quality of Code and Contribution Guidelines

• I have read the contribution guidelines.

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 85.44%. Comparing base (8f1c7b1) to head (13e4e04).

Additional details and impacted files

@@           Coverage Diff           @@
##              dev    #1435   +/-   ##
=======================================
  Coverage   85.44%   85.44%           
=======================================
  Files          35       35           
  Lines        1965     1965           
  Branches      370      370           
=======================================
  Hits         1679     1679           
  Misses        213      213           
  Partials       73       73           

Flag	Coverage Δ
unittests	85.39% <ø> (ø)

Flags with carried forward coverage won't be shown. Click here to find out more.

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.