Fix OpenGLSurface colorscale shifting as surface moved

[alembcke]

Overview: What does this pull request change?

Fixes a bug in OpenGLSurface when using colorscale where moving the surface caused the colors to shift.

Motivation and Explanation: Why and how do your changes improve the library?

Fixes issue #3115.

Links to added or changed documentation pages

N/A

Further Information and Comments

Video for comparison with linked issue:

Test.mp4

I think that this is a good implementation for fixing this issue, but please let me now if it has any knock-on effects I may not have considered.

Reviewer Checklist

• The PR title is descriptive enough for the changelog, and the PR is labeled correctly
• If applicable: newly added non-private functions and classes have a docstring including a short summary and a PARAMETERS section
• If applicable: newly added functions and classes are tested

[alembcke]

It looks like #3134 fixed this issue, so closing the pull request and closing issue #3115.