GroupBy + optional Join logic HQL, JsonB -> Jackson serialization

Enables GROUP BY clause and updates joins. New method of generating joins will add additional clauses to FROM, and add an equality check into the WHERE clause. When Hibernate reads this it transforms it into a cross join, which while not perfect, will allow for joins without defining associative entities in the DTO.

Also includes update to switch from JsonB to Jackson (which works with autovalue)

core/src/main/java/org/eclipsefoundation/core/config/CustomJacksonConfiguration.java

+package org.eclipsefoundation.core.config;
+
+import java.text.SimpleDateFormat;
+
+import javax.inject.Singleton;
+
+import org.eclipsefoundation.core.helper.DateTimeHelper;
+
+import com.fasterxml.jackson.databind.ObjectMapper;
+import com.fasterxml.jackson.databind.PropertyNamingStrategies;
+
+import io.quarkus.jackson.ObjectMapperCustomizer;
+
+/**
+ * Sets up Jackson with default API formatting standards.
+ * 
+ * @author Martin Lowe
+ *
+ */
+@Singleton
+public class CustomJacksonConfiguration implements ObjectMapperCustomizer {
+
+    @Override
+    public void customize(ObjectMapper objectMapper) {
+        objectMapper.setPropertyNamingStrategy(PropertyNamingStrategies.SNAKE_CASE)
+                .setDateFormat(new SimpleDateFormat(DateTimeHelper.RAW_RFC_3339_FORMAT));
+    }
+
+}