🔨 Add default metrics to Engine

[samet-akcay]

📝 Description

• Metric values in Engine is currently None. When Engine is used with default values, the validation step is not run since there is no metric. Due to this there is no test results. This PR adds AUROC and F1Score as the default metrics to both image and pixel level metrics.
• 🛠️ Fixes #1747

✨ Changes

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• [ ] 🐞 Bug fix (non-breaking change which fixes an issue)
• [x] 🔨 Refactor (non-breaking change which refactors the code base)
• [ ] 🚀 New feature (non-breaking change which adds functionality)
• [ ] 💥 Breaking change (fix or feature that would cause existing functionality to not work as expected)
• [ ] 📚 Documentation update
• [ ] 🔒 Security update

✅ Checklist

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• [ ] 📋 I have summarized my changes in the CHANGELOG and followed the guidelines for my type of change (skip for minor changes, documentation updates, and test enhancements).
• [ ] 📚 I have made the necessary updates to the documentation (if applicable).
• [ ] 🧪 I have written tests that support my changes and prove that my fix is effective or my feature works (if applicable).

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[ashwinvaidya17]

I see that some tests are failing as they directly access pixel_metric_names