Improve keyboard nav

[balloob]

Breaking change

Proposed change

Improve keyboard nav for the tracing UI. The only thing that's still not ideal is that the graph will focus the next element when tabbing through it. Is this on purpose @thomasloven? It makes it impossible to use just the keyboard and the graph to browse some details of a step. It's still possible right now via the arrow buttons that come after the graph.

Screenshot.2021-04-01.at.14.51.09.mp4

Type of change

• Dependency upgrade
• Bugfix (non-breaking change which fixes an issue)
• New feature (thank you!)
• Breaking change (fix/feature causing existing functionality to break)
• Code quality improvements to existing code or addition of tests

Example configuration

Additional information

• This PR fixes or closes issue: fixes #
• This PR is related to issue or discussion:
• Link to documentation pull request:

Checklist

• The code change is tested and works locally.
• There is no commented out code in this PR.
• Tests have been added to verify that the new code works.

If user exposed functionality or configuration variables are added/changed:

• Documentation added/updated for www.home-assistant.io

[thomasloven]

It was added as an accessibility feature that I later realized 1000% missed the goal and actually hurts accessibility for exactly this reason.
It's not trivial to remove, unfortunately, but I'll get on it.