Improve progress tracking for triplet import

Author: DarthMax

progress-tracking/src/main/java/org/neo4j/gds/core/utils/progress/tasks/Progress.java

@@ -30,6 +30,10 @@ public interface Progress {
 
     @Value.Lazy
     default double relativeProgress() {
+        if (volume() == Task.UNKNOWN_VOLUME) {
+            return Task.UNKNOWN_VOLUME;
+        }
+
         // progress can be larger if the volume was estimated too low (such as for cypher projections)
         return progress() >= volume()
             ? 1.0D

triplet-graph-builder/src/main/java/org/neo4j/gds/projection/GraphImporter.java

@@ -82,7 +82,7 @@ public static Task graphImporterTask(int taskVolume) {
         return Tasks.task(
             "Graph aggregation",
             Tasks.leaf("Update aggregation", taskVolume),
-            Tasks.task("Build graph store", Tasks.leaf("Nodes"), Tasks.leaf("Relationships"))
+            Tasks.task("Build graph store", Tasks.leaf("Nodes", 1), Tasks.leaf("Relationships", 1))
         );
     }