Apply text-keep-upright after text-offset

[anandthakker]

Closes #2350

[ChrisLoer]

I think there's a collision problem here: the CollisionFeature for a label will get its box from the Shaping, which assumes it's upright, but then if the quads are drawn flipped their offsets won't match the offsets of their collision boxes. We re-generate the collision tile every time we do placement, so it's no problem to update the collision boxes, but we may want to move the text-offset logic from CollisionFeature (which is just generated at tile parse time) to CollisionTile#insert/placeCollisionFeature.

[ansis]

I think this change makes sense but are there any cases where the current behavior is the desired one? Is this a breaking change?

[anandthakker]

@ChrisLoer looks like the collision problem already exists -- filed as a separate issue here: #4798

[anandthakker]

@jfirebaugh got confirmation from @nickidlugash that it's reasonable from the carto team's point of view to consider this a bug fix.

[ansis]

Looks good to me! Thanks for looking through the details of how this interacts with *-anchor properties, etc

This should be good to merge and I'll rebase #4781 on it

[jfirebaugh]

Do the integration tests pass in -native?

[anandthakker]

@jfirebaugh just chatted with @ansis about this when I realized I'd forgotten to mark them ignored -- since the shaders here are already ahead of native, he's going to make sure this fix is included in the stuff he's working on.