Add compatibility for keyboard events (keyCode constants) to data.js

Based on this issue: https://github.com/processing/p5.js/issues/7876 looks like the data.js add-on is not allowing the 1.x use: https://editor.p5js.org/ksen0/sketches/cvGEDgY_0 - looks like it provides compatibility for touch/mouse but not keyboard.

We've in the past combined data with events; it may also be useful to relabel the add-on in the editor from "Data Structures" to "Data & Events." I think this combination still makes sense because it contains various usages where the 2.0 breaking changes have the goal of more consistency - but if others think it would be better to split them into data and events, for example, I am also happy to support (with the attendant editor updates)

This issue includes reinstating 1.x constants (LEFT_ARROW) and keyboard events that have been changed (reviewing hem first; keyIsPressed, keyTyped, keyReleased, keyPressed, keyIsDown).