Refine display of test failures in VS Code

[connor4312]

• Improve the display of test messages in the editor, especially when there's lots of noise https://github.com/microsoft/vscode/pull/233137

• Make running tests from the explorer a better experience https://github.com/microsoft/vscode/pull/233453

  • migrate testing.openTesting -> testing.automaticallyOpenResults to be more accurate and discoverable
  • use a single click action for 'opening' tests in the explorer. This aligns with the file explorer.
  • with that, remove the inline "go to test" action (keep in the context menu for tests with children)
  • turn off the followRunningTest setting by default, it's noisy and people have raised issues over this
  • remove the unused "auto run delay" setting (not used since the testing API was finalized)

[connor4312]

To verify, create a few different test failures. Have some that fail with exceptions and some that have an expected vs actual output. Verify things are displayed sensibly, both the label text and label itself.