[ML] Jobs List expanded row tabs not navigable

[aphelionz]

Steps to reproduce (assumes ChromeVox or similar)

(Presumes a job has already been created in Machine Learning)

1. Open Kibana in a new tab
2. Tab to Machine Learning
3. Tab to the expand row button on the right side of the main table's data row
4. Press enter to see the job expand into its detail view
5. Try to use keyboard navigation to get to the tabs below

Actual Result
6. User cannot reach the tabs via the keyboard

Expected Result
7. User should be able to navigate to the tabs using the keyboard

Category: #18866 Kibana 6.3 Meta Issues
Relevant WCAG Criteria: 2.1.1 Keyboard Accessible

[elasticmachine]

Pinging @elastic/ml-ui

[peteharverson]

Fixed for 6.4.0 by rewrite of Jobs List to EUI / React in #19758