TitleBar control calculation of padding is incorrect

### Describe the bug

The titlebar control does not take the scale factor into account when calculating the widths of the columns used for padding, resulting in incorrect positioning of elements.

### Steps to reproduce the bug

The code here: https://github.com/microsoft/microsoft-ui-xaml/blob/689477e7edfd3d33db6e63dd251aac3b4e159bab/src/controls/dev/TitleBar/TitleBar.cpp#L400-L411

needs to take the scale factor into account by dividing `rightColumnInset` (value in physical pixels) by the scale factor.

### Expected behavior

_No response_

### Screenshots

_No response_

### NuGet package version

WinUI 3 - Windows App SDK 1.7 Preview 1: 1.7.250208002-preview1

### Windows version

Windows 11 (24H2): Build 26100

### Additional context

_No response_

Start in src/controls/dev/TitleBar/TitleBar.cpp at lines 400-411 and inspect how rightColumnInset and the scale factor are used in the column-width calculation. Verify the behavior at a non-default display scale; done means the padding and titlebar elements are positioned correctly when the scale factor changes.

Written by the indexing model from the issue text.