Updating TypeHelper to support all C* types

I refactored TypeHelper to use org.apache.cassandra.db.marshal.TypeParser which allowed me to get rid of most of the code in TypeHelper. Using TypeParser gives us support for all of the C* types. This did however necessitate some changes to test code in IntraServiceITest. The test was previously specifying types as UTF-8 and int32. I to change those to UTF8Type and Int32Type respectively. You also find that I had to refactor the compositeTest method to parse out the buffers.

If we're good with these changes, I'll update examples in the docs as well.