HHH-7902 Replace JDBC proxies with a set of contracts/helpers

HHH-7902 Merged JdbcResourceRegistry into JdbcCoordinator.  Parts of
LogicalConnection moved into JdbcCoordinator as well.

HHH-7902 Replaced Statement#close and ResultSet#close calls with
JdbcCoordinator#release

HHH-7902 Enforced the use of StatementPreparer, instead of Connection

HHH-7902 ResultSetExtractor.  Replaced all instances of execute,
executeQuery, executeUpdate, etc.

HHH-7902 Refactored AbstractReturningDelegate to give access to
jdbcCoordinator

HHH-7902 Corrected test failures

HHH-7902 Removed resource registry use from JdbcIsolation workers

HHH-7902 Corrected a few bugs in JdbcCoordinator and ResultSetExtractor.

HHH-7902 ResultSetExtractor -> ResultSetReturn.  Reworked proxy tests to
test the new APIs.