Add support for Accumulo Translator

Teiid added Accumulo translator in Teiid 8.7 version. This translator comes with few extension metadata properties. This translator also supports import of metadata if the data is defined in the Accumulo.

Designer needs to add, "Model Extension Defs" and validate the import process through Teiid Connection Importer.

BTW, I tried with latest 8.4 nightly it did not work, and did not give any errors out. Just said could not create VDB, no error logs in server. I added the extension model defn manually.

The translator docs can be found at https://docs.jboss.org/author/display/TEIID/Apache+Accumulo+Translator