fix: port data grid nav fix to fast-element-1

[scomea]

📖 Description

Keyboard events emitted from a data grid cell when a cell's internal navigation is active can incorrectly move focus in the parent grid. Rather than rely on authors to intercept these events the cell component can prevent their propagation.

Additionally, this change adds

a simple 'defaultCellFocusTargetCallback` function that authors can use to move focus to the first element of a cell.
an example of a grid with cells with internal focus targets and internal nav queue
fixes code that detects the current active element to work within shadow doms

This is a port of this pr:
https://github.com/microsoft/fast/pull/6754/files

🎫 Issues

Requested back port of a bug fix.

👩‍💻 Reviewer Notes

📑 Test Plan

✅ Checklist

General

• [ x] I have included a change request file using $ yarn change
• I have added tests for my changes.
• [] I have tested my changes.
• I have updated the project documentation to reflect my changes.
• I have read the CONTRIBUTING documentation and followed the standards for this project.

Component-specific

• I have added a new component
• I have modified an existing component
• I have updated the definition file
• I have updated the configuration file

⏭ Next Steps