If there are multiple trx files, only render the results for the newest one for a given assembly

[kzu]

Since each test run actually emits a different file name by default when running dotnet test -l trx.
Make it the default too.

The option could be:

• -l|--latest false (to render all, why would you want that?)

[kzu]

This should be the default behavior anyway and built-in, and now is!

We now keep the outcome of the most recently run test (by its constant test id) when processing multiple trx files, wihch are now all aggregated too. If you don't want aggregation, you can simply run the tool from each folder in turn multiple times (i.e. just run a trx file search first with powershell and pass --path for each).