[BUG]: Angle corrections: Broken UI for rectangular meshes

[gandy92]

Describe the bug

My UBL mesh is of size 7 x 5 and for this, the angle corrections UI shows the indicator inside the data table:

Expected behavior
Same as with meshes where the number of points in x- and y direction is the same

[jneilliii]

I'll see what I can do to resolve this when I can. I think that table rendering logic assumes an equal grid, but it was made by another contributor so will take a while to verify/adjust.