Fix overlapped button, ImGui::Indent should also consider DPI scale

[iaomw]

As the title, there is a button overlapped by other GUI elements while resolution scale is larger than 100%. #92
Case ImGui::Indent also need consider DPI scale on Windows.

However, the real problem might be GLFW. It's using virtual resolution on macOS but real pixel resolution on Windows.
Eventually, it will have side-effect on ImGui.

Tested on:
Windows 10 Pro 21h2
macOS BIg sur 11.6.5

Not tested on Linux.

[hyv1001]

suggest naming: float getConentScale() const and float getIndentScale() const

[hyv1001]

Thx for your awesome work, I will test it on Linux!
There are some suggestions about the function naming, plz check.

[iaomw]

Although glfwGetWindowContentScale only takes roughly 0.03ms on my CPU, it might be better to cache the result.
I was considering saving the result into one of classes: SurfaceIO, SurfaceRHI, UIState. After reading the source code, I am not sure which one is the best choice.

[hyv1001]

Although glfwGetWindowContentScale only takes roughly 0.03ms on my CPU, it might be better to cache the result. I was considering saving the result into one of classes: SurfaceIO, SurfaceRHI, UIState. After reading the source code, I am not sure which one is the best choice.

I think it's a UI-related variable, so SurfaceUI or UIState may be reasonable to store it.