Fix/ghes sarif baseurl - action.yml declaration; Centralized reading of input from utils as per style

[p4r53c]

Added declaration to action.yml
Added centralized reading of input from utils

[github-actions]

Thank you for your submission, we really appreciate it. Like many open-source projects, we ask that you sign our Contributor License Agreement before we can accept your contribution. You can sign the CLA by just posting a Pull Request Comment same as the below format.

---

I have read the CLA Document and I hereby sign the CLA

---

_{You can retrigger this bot by commenting recheck in this Pull Request. Posted by the CLA Assistant Lite bot.}