To draw the overlay stats in columns the strings must be measured to
find the longest one. In some circumstances this measurement can be
incorrect. We draw the text with a specific size yet do not explicitly
set the size before calling BLF_size. This patch properly sets the size
so the measurement will match what will be used for output.

See T88799 for examples of measurement failure.

Note that this one-line patch should look wrong to anyone without prior
experience with our (wonky) UI scaling code. The call to BLF_Size does
indeed need dpi multiplied by pixelsize. This is because U.dpi is not
actually DPI but dpi divided by U.pixelsize. Yes, our dpi changes if
you simply change to "wide lines". So this multiplication is needed to
get back actual dpi.