ArrayTile.{cols | rows} calls boxing fix

[pomadchin]

Overview

Since GT 3.x we had a regression where all calls to cols / rows were boxed. This lead to regressions in MutableArrayTile.{set / update / etc} functions. For more details see #3427, #3428, #3429 and #3432

This PR clarifies Grid inheritors cols / rows function types to help with the specialized calls dispatch.

Checklist

• [x] ./CHANGELOG.md updated, if necessary. Link to the issue if closed, otherwise the PR.
• [x] Benchmark added for bug-fix or new feature

Demo

Can be reproduced via:

$ sbt project bench; benchOnly geotrellis/raster/GridBoxingBench.scala

Closes #3427 Closes #3432

[pomadchin]

Going to leave here a link to this repo, for history https://github.com/pomadchin/specialization-benchmark