Move FlowDownStreamRunDeclarer.java from build-flow-plugin to buildgraph-view

[FIXED JENKINS-34516] [FIXED JENKINS-32499]

Author: pskumar448

pom.xml

@@ -130,12 +130,6 @@
             <artifactId>jgrapht-jdk1.5</artifactId>
             <version>0.7.3</version>
         </dependency>
-        <dependency>
-            <groupId>org.jenkins-ci.plugins</groupId>
-            <artifactId>buildgraph-view</artifactId>
-            <version>1.0</version>
-            <optional>true</optional>
-        </dependency>
 
         <dependency>
             <groupId>junit</groupId>