Make solvePart01 and solvePart02 Asyncronous

[ABausG]

My solution yesterday was taking quite long (>5 minutes) I think there could be some time saved if the solve function where asynchronous so we could use Future.wait to run multiple calculations in parallel

[S-ecki]

This would be a great idea! We could also use Isolates in that case!
I am not participating in this year's AoC as I have my plate full - but if you would be open to make a PR with the change, I would be happy to accept it!