Refactor SpiExpressionRequest split append() into append() and parse()

- append() adds to the sql with NO parsing
- parse() adds to the sql with parsing to replace logical bean paths into table alias placeholder + db column

ebean-core/src/test/java/io/ebeaninternal/server/expression/TDSpiExpressionRequest.java

@@ -49,6 +49,12 @@ public class TDSpiExpressionRequest implements SpiExpressionRequest {
     return this;
   }
 
+  @Override
+  public SpiExpressionRequest parse(String expression) {
+    sql.append(expression);
+    return this;
+  }
+
   @Override
   public void addBindEncryptKey(Object encryptKey) {