Design Proposal: Add a flag to dotnet watch to clear the screen when the process exits.

I think it would be useful to have an optional flag added for the dotnet watch command that clears the screen when a file change occurs. When I have multiple watchers running for different components, it can be helpful to keep the screen clean and only show the most recent changes.

Watch commands for other tools do this by default, and while I think it's generally helpful not to clear the screen I think it would be beneficial for users (as well as being relatively simple to implement).

I would be interested in investigating this and creating a PR myself to implement this. This was supposed to be labled as a "Design Proposal" (followed link from Contributing docs) but it doesn't look like that happened.