Display latest build status per workflow as the icon in the workflow list

**Is your feature request related to a problem? Please describe.**
Builds do fail sometimes. That is part of the nature of a CI system. I want to notice a failed build as quickly as possible

**Describe the solution you'd like**
The extension has a "Workflows" list. It correctly lists all the workflows. But I have to click on each of the workflows to open the list with the build result history. Most of the time, I am only interested in the status of the latest run.
The green check mark or red x icon should be displayed left to each workflow name depending on the outcome of the latest run for that workflow.

**Additional context**
I just installed the extension the first time. I like to see my build status in VSCode to be able to quickly act when a build fails (which might block the progress of a whole team in some cases).

Start by locating the extension's Workflows list and the data used to show each workflow's run history. Add the latest run result beside each workflow name, using a green check or red X as appropriate, and verify that the list reflects the outcome of the latest run.

Written by the indexing model from the issue text.