Misc fixes

• Fixed required annotation error message
• Making a return type optional (assumes void) and fixing validation rule for void returns
• Disable camel case directive name rule
• Fix descriptions over namespaces, imports, directives, interfaces and roles
• Make parameters parenthesis options for directive definitions
• Added parseType
• Switch on kind improvement
• Added annotation callback
• novisit annotation for types and enums
• Operation returns void validation fix
• Required field from type in valid annotation check