Adjust orthographic camera gizmo with respect to keep_aspect setting

[jsjtxietian]

Fixes #90589

[MajorMcDoom]

Thanks for tackling this!

A couple of issues:

• When using Keep Height, the aspect ratio is no longer maintained. Instead, it's always a square.
• When using Keep Height, the handle is still placed on the right side of the gizmo, instead of on the top. This means it's visually reflecting the width, and using that resulting value to set a value that will become the height, which is wrong.
  

[MajorMcDoom]

I've attached an image of the expected behaviour when the size is set to 2.0. Hope this helps!

[jsjtxietian]

I see, thanks for your help!

It should feel more correct now.

[MajorMcDoom]

I see, thanks for your help!

It should feel more correct now.

Works correctly now as far as I can tell! Just waiting for a review now. Thanks again. :)

[Calinou]

Tested locally, it works as expected. Both Keep Height and Keep Width orthgographic gizmos render correctly now, even if the base aspect ratio is changed in the project settings (when changing the window width/height project settings).

Code looks good to me.

Before	After

Example of the sizes being correct now:

[akien-mga]

Thanks!