Support a way to track findings without using finding number

[hans-cyfrin]

For now, if there is a need to change severity or close a higher severity issue, the lower severity issue numberings are affected.
This brings confusion during the mitigation review due to inconsistent numbering.
To handle both scenarios, it would be great if we can utilize the GitHub issue number as a unique id of each finding and provide that in the report for the protocols.

Now:
7.1.1 Example high issue title
Description: Example description ....

Desired:
7.1.1 Example high issue title
Finding ID: ISSUE-04
Description: Example description ....

Might need to add a column in the summary table too.