feat: Display TreePanel in SideNav for /newui/processes

spiffworkflow-frontend/src/a-spiffui-v3/views/StartProcess/Processes.tsx

@@ -1,7 +1,20 @@
 import ProcessModelTreePage from './ProcessModelTreePage';
 import { ProcessModelAction } from '../../interfaces';
+import {useEffect} from 'react';
+import {TreePanel} from './TreePanel';
+
+export default function Processes({setNavElementCallback}: {setNavElementCallback: Function}) {
+
+  useEffect(() => {
+    if (setNavElementCallback) {
+      setNavElementCallback(
+        <TreePanel
+          processGroups={[]}
+        />,
+      );
+    }
+  }, [setNavElementCallback]);
 
-export default function Processes() {
   return (
     <ProcessModelTreePage
       processModelAction={ProcessModelAction.Open}

spiffworkflow-frontend/src/routes/SpiffUIV3.tsx

@@ -230,7 +230,12 @@ export default function SpiffUIV3() {
                       />
                     }
                   />
-                  <Route path="/processes" element={<Processes />} />
+                  <Route
+                    path="/processes"
+                    element={<Processes
+                      setNavElementCallback={setAdditionalNavElement}
+                               />}
+                  />
                   <Route
                     path="/processes/:process_group_id"
                     element={<Processes />}