refactor(src): 调整矩阵题列标签样式并初始化选择题答案模型

- 移除了矩阵题列标签的 text-align:center 样式
- 初始化了选择题的答案模型，默认值分别为空字符串和空数组

src/utils/QuestionJsons/MartrixQuestion.js

@@ -29,7 +29,7 @@ export default {
     ],
     [
       {
-        option: '<p style="text-align:center">列标签1</p>',
+        option: '<p>列标签1</p>',
         id: '1049201',
         type: 2,
         is_other: 0,

src/views/Design/components/Questions/Choice.vue

@@ -107,8 +107,8 @@ import { defineAsyncComponent } from 'vue';
 
 // 是否是预览
 const isPreview = defineModel('isPreview', { default: false, type: Boolean });
-const choiceValue = defineModel('answer', { default: '1', type: String });
-const value = defineModel('checkboxAnswer', { default: [1, 2], type: Array });
+const choiceValue = defineModel('answer', { default: '', type: String });
+const value = defineModel('checkboxAnswer', { default: [], type: Array });
 const errorMessage = defineModel('errorMessage', { default: '', type: String });
 const Contenteditable = defineAsyncComponent(() => import('@/components/contenteditable.vue'));
 defineProps({