[11.x] Allow sorting of route:list by multiple columns, ASC and DESC

[fgaroby]

This PR improves the new route:list multiple columns sort, by allowing ASC or DESC for each factor.

For example, we can do this now :

artisan route:list --sort=domain,uri:DESC

Which first sorts the list by domain column ASC (default value) and then by the uri column DESC.

[taylorotwell]

Thanks for your pull request to Laravel!

Unfortunately, I'm going to delay merging this code for now. To preserve our ability to adequately maintain the framework, we need to be very careful regarding the amount of code we include.

If possible, please consider releasing your code as a package so that the community can still take advantage of your contributions!

If you feel absolutely certain that this code corrects a bug in the framework, please "@" mention me in a follow-up comment with further explanation so that GitHub will send me a notification of your response.