Set default MatView Extension Properties for JDG materialization

When a view is being materialized for JDG, set the following extension properties:

teiid_rel:MATVIEW_AFTER_LOAD_SCRIPT -

   execute {jdgsourcemodelname}.native(''swap cache names'');

teiid_rel:MATVIEW_BEFORE_LOAD_SCRIPT -

  execute {jdgsourcemodelname}.native(''truncate cache'');

teiid_rel:MATERIALIZED_STAGE_TABLE -

 
  {jdgsourcemodelname}.{stagingTable}

where

as the new JDG Source Model that is created.

note: do not add tic's around these, like 'execute......),'
but do add the double tic's inside the native call