[DataGrid] Smoother resizing

[f4n0]

Pull Request

📖 Description

Fix DataGrid not resizing right when there is aside and ResizeType = null

The newer version does not account the sidebar when resizing!
repro: https://f4n0.github.io/BlazorGenerator/list
Code: https://github.com/f4n0/BlazorGenerator/blob/master/src/BlazorGenerator/Components/DataGrid/ListDataGrid.razor#L23

🎫 Issues

👩‍💻 Reviewer Notes

📑 Test Plan

✅ Checklist

General

• 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 added Unit Tests for my new component
• I have modified an existing component
• I have validated the Unit Tests for an existing component

⏭ Next Steps

[vnbaaij]

Can you include a picture of what the issue is? I can't deduce from the repro link what the problem is.

[f4n0]

In this video i show the problem:
When the sidebar is open and start resizing the column, it will have the same offset as the SideBar width. When sidebar closed, the gap is not so evident!

recording.mp4

With the fix in this PR:

recording.2.mp4