fix:Github ID type check

[Codered9]

Description

Added Github ID type check (should be User else return false) in Frontend and Backend using Github API.

Fixes #202

Type of change

Please delete options that are not relevant.

• [x] Bug fix (non-breaking change which fixes an issue)

Checklist:

• [x] My code follows the style guidelines of this project
• [x] I have performed a self-review of my own code
• [x] I have commented on my code, particularly in hard-to-understand areas
• [x] My changes generate no new warnings