Test summary should show duration time in a more user-friendly format

The test summary shows output like the following:

```
Tests run: 28, Errors: 0, Failures: 0, Skipped: 0. Time: 407.0531913s
```

The duration listed at the end is rather computer-y and would benefit from being more user-friendly. One option is to use the [same pattern that vstest uses](https://github.com/microsoft/vstest/blob/82c581ff79a09354ce2ab007713319f629568aa9/src/vstest.console/Internal/ConsoleLogger.cs#L238-L253). Another option would be to format it with [Humanizer](https://github.com/Humanizr/Humanizer?tab=readme-ov-file#humanize-timespan).