This commit moves a lot of test setup logic to runner.sh. Also
passes the right commands to the regression infrastructure to create
appropriate users and run tests as a regular user.
Constraints on regular PostgreSQL tables need to be validatated so
that they don't have a foreign key constraint that references a
hypertable, as this is not yet supported. This change fixes a bug in
this validation caused by not checking for the proper node types when
parsing a CreateStmt node. The CreateStmt is now also parsed in the
DDL end hook, instead of the processUtility hook, which ensures that
the CreateStmt node has been run through parse analysis. The parse
analysis changes the contents of the node to be more consistent across
different CREATE statements. For instance, a CREATE LIKE statement
will look more similar to a regular CREATE statement after parse
analysis.