test(listbox): keyboard navigation rendering tests

[johanlahti]

Motivation

• Break out keyboard nav tests into its own listbox-keyboard-nav.spec.js file (for performance and readability)
• Add a scenario for keyboard navigation involving navigate rows with arrow keys, selecting, tabbing and confirming.

Requirements checklist

• Api specification
  • Ran yarn spec
    • No changes OR API changes has been formally approved
• Unit/Component test coverage
• Correct PR title for the changes (fix, chore, feat)

When build and tests have passed:

• Add code reviewers, for example @qlik-oss/nebula-core