Add new icon for run all failed tests

[luabud]

Hey there! Now that there will be a "Test: Rerun Failed Tests" command, I was wondering if we could have a new official icon (perhaps updated to the vscode-icons repo, if it's not too much work) that we could display on the test explorer (only when there is at least one failed test in the view)?

We have custom ones at https://github.com/microsoft/vscode-python/blob/main/resources/dark/run-failed-tests.svg and https://github.com/microsoft/vscode-python/blob/main/resources/light/run-failed-tests.svg, but we figured it'd be best to have something provided "officially" by VS Code

[miguelsolorio]

How about this?

This also maps with our other run icons:

[luabud]

@misolori I love it!

cc @karthiknadig

[miguelsolorio]