chore: Modified bug issue template to add checkbox to report potential regression.

[ashishdhingra]

Issue #, if available:

Description of changes:

• Modified bug issue template to add checkbox to report potential regression.
• Added GitHub action to add/remove label potential-regression when issue is created/edited.

NOTE:

• The GitHub action code was ported from CDK repo.
• The label potential-regression would need to be created manually (we could use color #FF6700 and description Marking this issue as a potential regression to be checked by team member to make it consistent across SDK repos)

Label potential-regression would make issue standout in the list and help engineers to handle high severity issues effectively.

Check all that applies:

• Did a review by yourself.
• Added proper tests to cover this PR. (If tests are not applicable, explain.)
• Checked if this PR is a breaking (APIs have been changed) change.
• Checked if this PR will not introduce cross-platform inconsistent behavior.
• Checked if this PR would require a ReadMe/Wiki update.

Check which platforms you have built SDK on to verify the correctness of this PR.

• Linux
• Windows
• Android
• MacOS
• IOS
• Other Platforms

By submitting this pull request, I confirm that you can use, modify, copy, and redistribute this contribution, under the terms of your choice.

[htami1717]

https://github.com/aws/aws-sdk-cpp/blob/main/.github/workflows/closed-issue-message.yml#L9C42-L9C52