chore: enable CodeQL, update branch protection policy, add issue automation

[MIchaelMainer]

Overview

Improve branch protection by requiring conversation resolution (signoff), require strict status checks including CodeQL, and add issue automation.

Testing Instructions

After merge into dev:

1. Open a new test PR and witness that there are now required status checks, all PR comments require resolution.
2. Create test issue and set the Resolution: Duplicate label on it. It should be automatically closed. This only tests the one action and the bot integration is working.

[github-advanced-security]

This pull request sets up GitHub code scanning for this repository. Once the scans have completed and the checks have passed, the analysis results for this pull request branch will appear on this overview. Once you merge this pull request, the 'Security' tab will show more code scanning analysis results (for example, for the default branch). Depending on your configuration and choice of analysis tool, future pull requests will be annotated with code scanning analysis results. For more information about GitHub code scanning, check out the documentation.

[sonarcloud]

Kudos, SonarCloud Quality Gate passed!   

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