GDST V&V: Clean up situations where the webworker fails

Problem: If the project does not compile, you can edit the table, but editing fires errors in the Verifier Webworker. This is because the Verifier needs a project that compiles and creates a valid DMO.

The fix will be to shutdown the Verifier when an error happens. The fix will not care what the error was, since usually it the errors are caused by missing or corrupt data and the verifier can not recover from this anyway.