Don't let users submit theorytabs if the artist isn't filled or is filled with only spaces

Right now there are 7 theorytabs with blank artists. I have an idea to stop more from coming which is simply to not let the user submit the theorytab if the artist isn’t filled

Fixed. Also all TheoryTabs with blank artists were removed. There were seven, as you mentioned. They all already had existing pages with correct artist populated.

Thanks @Vaz123. Thank you for your persistence in reminding us to patch this.