Add enhancements to more efficiently handle large documents/files

The default strategy of Teiid is to copy the inputstream sent back from CXF (or anything returning a Source/DataSource). To reduce latency this copy should be performed during read, rather than all at once.

Ideally we should investigate the CXF internals to see if we can get a handle to a temp file, which would completely eliminate the need for a copy. Alternatively or in addition to this approach, the ws translator should offer an option to return a single use SQL/XML value to the engine.