[Peek] Images do not size to fill the entire client area

### Microsoft PowerToys version and release channel

0.102 (current main)

### Installation method

Dev build in Visual Studio

### Area(s) with issue?

Peek

### Steps to reproduce

Open an image with Peek.

### ✔️ Expected Behavior

The image is opened and is sized appropriately to fill the client area of the window.

### ❌ Actual Behavior

Gaps or 'seams' often appear between the image and the window chrome.

### 1024x1024 opened on 1920x1080 display at 125% scaling:

Bottom gap:

### 1428x582 opened on 1920x1080 display at 125% scaling

Left + right gap:

### 1681x67 opened on 1920x1080 display at 125% scaling

Left + right gap:

### 1408x768 opened on 3840x2160 display at 175% scaling

Bottom gap:

### 1280x896 opened at 3840x2160 display at 175% scaling

Bottom gap:

### 1024x1024 opened on 3840x2160 display at 175% scaling

Bottom gap:

### 1080x1920 opened on 3840x2160 display at 175% scaling

Tall bottom gap:

Gaps are consistent at each of these sizes. Note that some of the instances of 'bottom gaps' here are also likely to include gaps at the top of the client area, but it is difficult to tell because of the title bar and client area being the same colour.

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### Additional Information

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### Other Software

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