MODE-2400: Adds support for GLOBAL TEMPORARY tables in DDL Sequencer

* Enhances the Teiid DDL Sequencer with supporting the CREATE GLOBAL
  TEMPORARY TABLE syntax, present in Teiid's BNF.

* Includes tests for basic case and specific test to ensure that an AS
  statement cannot be appended since this is illegal.
Merge pull request #1356 from Teiid-Designer/MODE-2400

MODE-2400: Adds support for GLOBAL TEMPORARY tables in DDL Sequencer