Convert navigating the PB UI with the keyboard Nightwatch test to a functional JS test under PHPUnit

Problem/Motivation

The Nightwatch test which involves navigating through the PB UI with the keyboard is failing. Since 99% of our tests are functional JS test under PHPUnit anyway, let's convert it to that.

Steps to reproduce

Proposed resolution

The failing test will be removed in 🐛 Fix tests Active , convert the test to a functional JS test under PHPUnit.