Add direct dependency to Jackson JSON-B and JSON-P in pom.xml.

Needed because the transitive dependency from AWS has been used before.
Thus this relates to IQSS#5274. As best practise, code should not rely on
those deps but add a direct dependency.

For the sake of working on IQSS#4260 (Java EE 8) at some point in the future, please
remember to refactor the code using Jackson (and Gson) and remove it
in favor of Java EE 8 native JSON-B and JSON-P support.

pom.xml

@@ -213,6 +213,16 @@
             <version>2.2.4</version>
             <scope>compile</scope>
         </dependency>
+        <!-- Should be refactored and removed once on Java EE 8 -->
+        <dependency>
+            <groupId>com.fasterxml.jackson.core</groupId>
+            <artifactId>jackson-core</artifactId>
+        </dependency>
+        <!-- Should be refactored and removed once on Java EE 8 -->
+        <dependency>
+            <groupId>com.fasterxml.jackson.core</groupId>
+            <artifactId>jackson-databind</artifactId>
+        </dependency>
         <dependency>
             <!-- required by org.swordapp.server.sword2-server -->
             <groupId>com.io7m.xom</groupId>