Add validation for sim title

[chrisklus]

From phetsims/perennial#326 and discussion with @jbphet and @zepumph:

The build process requires a title for any language it's building, but rosetta allows a translation to be submitted without a title. This would require a large maintenance release to fix on the chipper side, so we agreed to add some validation in rosetta. @jbphet is up for this, thanks! I'm happy to review the UX when you're finished if you'd like a tester.