[SPARK-3123][GraphX]: override the "setName" function to set EdgeRDD's name...

[SPARK-3123][GraphX]: override the "setName" function to set EdgeRDD's name manually just as VertexRDD does.

Author: uncleGen <hustyugm@gmail.com>

Closes #2033 from uncleGen/master_origin and squashes the following commits:

801994b [uncleGen] Update EdgeRDD.scala

graphx/src/main/scala/org/apache/spark/graphx/EdgeRDD.scala

@@ -37,7 +37,15 @@ class EdgeRDD[@specialized ED: ClassTag, VD: ClassTag](
     val targetStorageLevel: StorageLevel = StorageLevel.MEMORY_ONLY)
   extends RDD[Edge[ED]](partitionsRDD.context, List(new OneToOneDependency(partitionsRDD))) {
 
-  partitionsRDD.setName("EdgeRDD")
+  override def setName(_name: String): this.type = {
+    if (partitionsRDD.name != null) {
+      partitionsRDD.setName(partitionsRDD.name + ", " + _name)
+    } else {
+      partitionsRDD.setName(_name)
+    }
+    this
+  }
+  setName("EdgeRDD")
 
   override protected def getPartitions: Array[Partition] = partitionsRDD.partitions