[KEYBOARD]: Tooltips in dashboard panel titles must be keyboard focusable

[1Copenut]

Steps to reproduce

1. Log into a Kibana instance that contains tooltips in the dashboard panels
2. Press the TAB key to navigate through focusable elements
3. Verify the dashboard tooltips do not receive focus, but do expand when hovered over with a mouse

Actual Result

• Tooltips only expand on mouse hover event

Expected Result

• Tooltips expand on mouse hover event and when they receive keyboard focus
• Tooltips are sibling elements to the H2, not a child element

Kibana Version: 7.13.1 8.0.0

OS: Windows 10

Browser: Chrome or Edge

Relevant WCAG Criteria: Understanding Success Criterion 2.1.1: Keyboard - Level A

[elasticmachine]

Pinging @elastic/kibana-accessibility (Project:Accessibility)

[elasticmachine]

Pinging @elastic/kibana-app-services (Team:AppServicesUx)

[1Copenut]

Did we remove the tooltips from dashboard panels? I pulled the latest main branch version to my local machine and they're not present in the sample data sets.

[vadimkibana]

Looking at code, it seems that the "i" icon is rendered when embeddable has a description.

[vadimkibana]

It appears when one sets description for a new visualization:

[elasticmachine]

Pinging @elastic/kibana-presentation (Team:Presentation)

[ThomThomson]

Bumped this to medium because we now allow users to more easily create Descriptions for their panels.