XMLSchema Visitor doesn't handle * imports

[dselman]

Create a CTO file that imports all types from a namespace using import ... *.

The visitor will fail with an error similar to below.

Generating XmlSchema for /Users/dselman/dev/models/build/markdown/ciceromark: Type * is not defined in namespace org.accordproject.commonmark

[GaneshPatil7517]

hey @dselman if this iisue is open assign ill work on this....