feat(tutorial): enhance help button visibility and add dialog tests

- Introduced a mechanism to hide the help button when modal dialogs are open by adding `helpButtonHidden` state in the tutorial controller.
- Updated various components to set the help button visibility based on dialog states.
- Added tests to verify help button visibility during reward and task confirmation dialogs.
- Created new E2E tests for dialog help button functionality across different assignment views.
- Refactored existing dialog components to utilize the new help button visibility logic.
- Added unit tests for `RewardConfirmDialog` and `TaskConfirmDialog` to ensure correct titles are rendered based on task type.
- Enhanced `HelpButton` component tests to validate visibility based on tutorial state.

frontend/src/components/child/TaskConfirmDialog.vue

@@ -1,7 +1,7 @@
 <template>
   <ModalDialog
     v-if="task"
-    title="Confirm Task"
+    :title="dialogTitle"
     :subtitle="task.name"
     :imageUrl="task.image_url"
     @backdrop-click="$emit('cancel')"
@@ -19,14 +19,19 @@
 </template>
 
 <script setup lang="ts">
+import { computed } from 'vue'
 import ModalDialog from '../shared/ModalDialog.vue'
 import type { Task } from '@/common/models'
 
-defineProps<{
+const props = defineProps<{
   task: Task | null
   childName?: string
 }>()
 
+const dialogTitle = computed(() =>
+  props.task?.type === 'kindness' ? 'Confirm Act' : 'Confirm Task',
+)
+
 defineEmits<{
   confirm: []
   cancel: []