[Improvement-15725][UI] The default option of project preferences can be clearable. (#15727)

* adjust the project preferences

dolphinscheduler-ui/src/views/projects/preference/use-form.ts

@@ -125,7 +125,13 @@ export function useForm() {
         item.validate.required = false
         item.span = 12
       }
-      Object.assign(item, { props: { style: 'width: 250px' } })
+      if (item.type === 'select') {
+        Object.assign(item, {
+          props: { style: 'width: 250px', clearable: true }
+        })
+      } else {
+        Object.assign(item, { props: { style: 'width: 250px' } })
+      }
     }
     return preferencesItems
   }

dolphinscheduler-ui/src/views/projects/task/components/node/detail-modal.tsx

@@ -130,7 +130,11 @@ const NodeDetailModal = defineComponent({
 
     const restructureNodeData = (data: INodeData) => {
       if (!data?.id) {
-        Object.assign(data, projectPreferences.value)
+        for (let item in projectPreferences.value) {
+          if (projectPreferences.value[item] !== null && item in data) {
+            Object.assign(data, { item: projectPreferences.value[item] })
+          }
+        }
       }
     }
 

dolphinscheduler-ui/src/views/projects/workflow/definition/components/start-modal.tsx

@@ -240,6 +240,16 @@ export default defineComponent({
           form.environmentCode = projectPreferences.value.environmentCode
         }
       }
+      if (projectPreferences.value?.alertGroups && variables?.alertGroups) {
+        if (
+          containValueInOptions(
+            variables.alertGroups,
+            projectPreferences.value.alertGroups
+          )
+        ) {
+          form.warningGroupId = projectPreferences.value.alertGroups
+        }
+      }
     }
 
     const updateWorkerGroup = () => {