Names of built-in sample projects are invalid

After kiegroup/kie-wb-common#1664 has been merged, all the example projects from kie-wb-playground with space in the name are reported as having invalid names.

To reproduce this just import "Evaluation process" in kie-wb, go to project settings, do any change and try to save -> you'll get invalid project name validation error.

I propose this fix by replacing all spaces in project names by underscores.