Bootstrap args WINDUP-346

Instead of doing it in scripts (WINDUP-346), this processes args in Bootstrap class.

If there's some refactoring and then the actual changes, do you want that to be 1 commit or 2?
Is it okay to merge this as is, and I can make it boot Forge and query it for parameters afterwards? That change would be really significat - you would need to boot Windup to look for all rulesets (defining the params), which currently happens in the windup-migrate-app operation.

Which means, that would be quite some refactoring. This PR can be included as is, without waiting for the above.