Use correct font in painter in **Memory Viewer** dialog.

[cristian64]

Although the font was set up in the Memory Viewer dialog's main widget, the viewport's painter that actually renders the text was still using the default font.

When a theme (other than System) was used, this resulted in the grid and the text having a mismatched size, which was specially noticeable when the font size was made large or small:

Before	After

Bonus changes: initial font size is no longer hardcoded to 15; now it's based on a percentage (+50%) of the size of the default font.

[dreamsyntax]

I'm not sure what was going on with your before screenshots... I see no change on Windows at least.
Unless I'm misunderstanding and you explicitly made it small for demonstrating the width?

Windows Before:

Windows After:

---

Linux Before:

Linux After:

Ctrl+Mouse Scroll seems to work the same on both builds.

[dreamsyntax]

The changes seem sane to me, I just don't notice any difference in my tests on both windows and linux (cachyos, kde, wayland)

If it fixes this issue for some other configurations, I don't have a problem with it being merged.
Feel free to merge when you are satisfied.

[cristian64]

I'm not sure what was going on with your before screenshots... I see no change on Windows at least.
Unless I'm misunderstanding and you explicitly made it small for demonstrating the width?

Before taking the screenshots, I had used the mouse wheel to increase the font size. Without this fix (i.e. the screenshot in the Before column), the grid grows to match the font size, but the text is rendered with a smaller font size.

I have now realized that the issue only manifests if the theme is not set to System. Could you confirm you can reproduce the problem with any other theme?

[dreamsyntax]

I have now realized that the issue only manifests if the theme is not set to System. Could you confirm you can reproduce the problem with any other theme?

Ah yep, thats what it was.
Reproduced on Windows