Stabilize statement order in Jelly distributions

Issue: RiverBench/RiverBench#120

src/main/scala/commands/PackageCommand.scala

@@ -385,11 +385,11 @@ object PackageCommand extends Command:
     val serializeFlow = (
       if metadata.streamTypes.exists(_.elementType == ElementType.Triple) then
         Flow[(DatasetGraph, Long)]
-          .map((ds, _) => ds.getDefaultGraph.asTriples)
+          .map((ds, _) => ds.getDefaultGraph.asTriples.toSeq.sorted)
           .via(EncoderFlow.graphStream(None, jOpt))
       else
         Flow[(DatasetGraph, Long)]
-          .map((ds, _) => ds.asQuads)
+          .map((ds, _) => ds.asQuads.toSeq.sorted)
           .via(EncoderFlow.datasetStreamFromQuads(None, jOpt))
       )
       .via(JellyIo.toBytesDelimited)

src/main/scala/util/RdfOrdering.scala

@@ -1,15 +1,27 @@
 package io.github.riverbench.ci_worker
 package util
 
+import org.apache.jena.graph.Triple
 import org.apache.jena.sparql.core.Quad
 
 object RdfOrdering:
 
+  given Ordering[Triple] with
+    override def compare(x: Triple, y: Triple): Int =
+      val cmpSubject = x.getSubject.toString.compareTo(y.getSubject.toString)
+      if cmpSubject != 0 then cmpSubject
+      else
+        val cmpPredicate = x.getPredicate.toString.compareTo(y.getPredicate.toString)
+        if cmpPredicate != 0 then cmpPredicate
+        else
+          x.getObject.toString.compareTo(y.getObject.toString)
+
   given Ordering[Quad] with
     def compare(x: Quad, y: Quad): Int =
       val cmpGraph = x.getGraph.toString.compareTo(y.getGraph.toString)
       if cmpGraph != 0 then cmpGraph
       else
+        // Repeated code because Quad and Triple don't implement a common interface
         val cmpSubject = x.getSubject.toString.compareTo(y.getSubject.toString)
         if cmpSubject != 0 then cmpSubject
         else