Implement scrolling performance metrics

### Description

The current scrolling performance testing for MAUI is in a separate repository (https://github.com/jonathanpeppers/maui-scrolling-performance). This issue proposes to migrate this project into the dotnet/maui repository and establish proper performance testing infrastructure for scroll performance.

## Proposed Solution
1. Migrate the [maui-scrolling-performance](https://github.com/jonathanpeppers/maui-scrolling-performance) project to dotnet/maui repository
2. Integrate with existing test infrastructure
3. Create automated performance tests for scroll performance
4. Add documentation for the performance test methodology

## Implementation Details

### Migration Steps
1. Create a new directory under `src/TestUtils/src/Microsoft.Maui.PerformanceTests` or similar location
2. Port the existing code from jonathanpeppers/maui-scrolling-performance
3. Update project references and namespaces

### Test Infrastructure
1. Develop a standardized framework for measuring scrolling metrics:
- Frames per second (FPS)
- Frame time consistency
- Memory usage during scrolling
- CPU usage during scrolling

2. Add test cases for different scenarios:
- ListView with various item templates
- CollectionView with different layouts
- ScrollView with various content
- Grid-based scrolling
- Different platforms comparison (iOS, Android, Windows)

### Integration with CI/CD
1. Add performance tests to the testing pipeline
2. Establish baseline performance metrics
3. Configure alerts for performance regressions

## Benefits
- Early detection of performance regressions
- Better understanding of scrolling performance across platforms
- Ability to measure improvements in scrolling performance
- Standardized methodology for testing and reporting scroll performance

## Related Work
- [maui-scrolling-performance](https://github.com/jonathanpeppers/maui-scrolling-performance) repository
- Existing performance testing infrastructure in dotnet/maui

## Additional Information
The original repository uses a specialized UI testing approach with frame counting and provides detailed performance metrics for different control types. This approach should be preserved while integrating with the existing test infrastructure.

### Public API Changes

None

### Intended Use-Case

Currently, there's no standardized way to test and validate scroll performance in MAUI applications within the main repository. The external repository by Jonathan Peppers provides a solution for this, but having it integrated into the main repository would allow for:
1. Consistent performance testing as part of CI/CD
2. Early detection of performance regressions
3. Benchmark capabilities for performance improvements
4. Better documentation of scroll performance characteristics

Start by reviewing the external maui-scrolling-performance repository and the existing performance testing infrastructure in dotnet/maui. Inspect src/TestUtils/src/Microsoft.Maui.PerformanceTests or the appropriate location, then map the migration, platform scenarios, metrics, CI integration, baselines, alerts, and methodology documentation. Done means the project is integrated and automated scroll-performance coverage reports the proposed metrics across the stated platforms.

Written by the indexing model from the issue text.