Add attribute for MySQL DB port

[glee2429]

Description

This PR is to add an attribute, DB PORT (stable).

Fixes # (issue)

How Has This Been Tested?

I added a test case for mocking the database and getting the port value.

Does This PR Require a Core Repo Change?

• [X] No.

Checklist:

• [X] Followed the style guidelines of this project
• [ ] Changelogs have been updated
• [X] Unit tests have been added
• [ ] Documentation has been updated

[linux-foundation-easycla[bot]]

• :white_check_mark:login: glee2429 / (7096019aff90772520f65471071052ea4fd0973e)

The committers listed above are authorized under a signed CLA.