Marker text size distorted during animations

[n-riesco]

Taken from #1607.

Here's a codepen that shows the issue.

[alexcjohnson]

And during zoom (by dragging an axis end or corner). @rreusser it was you who put in the inverse-distortion code for points and lines, right? Should be easy to extend to text?

[etpinard]

Closed via #1616 by @rreusser