3123 - Github - Update Issue action

[karlocehulic19]

Description

This is a Draft PR, because I am not sure how to implement API to send null as a milestone to GitHub. API reference is here, other than that, everything else I believe is implemented

Closes #3123

Type of change

• New feature (non-breaking change which adds functionality)

How Has This Been Tested?

Manually tested, automation tested for the getMilestone option method, and perform method,

Checklist:

• [ - ] My code follows the style guidelines of this project (not yet since this is a draft PR)
• [ + ] I have performed a self-review of my own code (on the fetures that work)
• [ + ] I have commented my code, particularly in hard-to-understand areas
• [ - ] I have made corresponding changes to the documentation (not yet since this is a draft PR)
• [ + ] My changes generate no new warnings
• [ + ] I have added tests that prove my fix is effective or that my feature works
• [ - ] New and existing unit tests pass locally with my changes (not yet since this is a draft PR)

[karlocehulic19]

Here are some pictures of what the current implementation of an empty string for the milestone value does: