Add Support to Upsert/Insert Ignore on PDB

- Fix tests: Fixes the h2 assumption as it requires more than one h2 engine.

src/test/java/com/feedzai/commons/sql/abstraction/engine/impl/abs/EngineCloseTest.java

@@ -123,7 +123,7 @@ public void setUp() throws DatabaseFactoryException {
     @Test
     public void closingAnEngineShouldFlushAndCloseInsertPSsAndCloseCachedPSs(@Capturing final Statement preparedStatementMock)
             throws DatabaseEngineException, SQLException, NameAlreadyExistsException {
-        assumeTrue(!ImmutableList.of("h2", "postgresql", "cockroach").contains(config.vendor));
+        assumeTrue(!ImmutableList.of("postgresql", "cockroach").contains(config.vendor) && !config.vendor.startsWith("h2"));
 
         engine.addEntity(buildEntity("ENTITY-1"));
         engine.addEntity(buildEntity("ENTITY-2"));