Add restart message to Output console message to confirm restart

[martypdx]

When using the output channel to diagnose problems, there is no visual indication when the problem gets fixed.

As a simple example, here is a new project where I forgot to installed eslint:

What you can't tell is that I went and fixed the problem by installing eslint and the eslint extension is happy and running as expected. However, it looks like the problem is still active because there has been no change to the console.

Now imagine diagnosing a more difficult setup issue, and you keep getting the same error as you try various fixes. And then you actually fix the problem but you move past it because you can't tell it worked. Assuming you notice what's going on, you still have to stop and manually go try and see if linting is working, or you just restart VSCode to figure out correct status. Good times.

A single line on successful restart would be very helpful!