feat: 添加学生提交系统功能

- 添加学生提交管理服务 (StudentSubmissionService, StudentSubmissionDetailService)
- 新增学生提交相关控制器 (StudentSubmissionController, StudentSubmissionDetailController)
- 添加学生提交数据传输对象 (StudentSubmissionDetailDto, StudentSubmissionSummaryDto)
- 新增学生提交相关页面组件 (StudentExamView, ExamDetailView, StudentCard等)
- 添加学生提交信息卡片组件 (SubmissionInfoCard, TeacherSubmissionInfoCard)
- 更新数据库迁移文件以支持提交系统

TechHelper.Client/Pages/Teacher/ExamDetailView.razor

@@ -0,0 +1,3 @@
+<MudPaper>
+	<MudText> EXAM NAME</MudText>
+</MudPaper>

TechHelper.Client/Pages/Teacher/StudentCard.razor

@@ -0,0 +1,7 @@
+@using Entities.DTO
+<h3>StudentCard</h3>
+
+@code {
+	[Parameter]
+	public StudentDto StudentDto{ get; set; }
+}

TechHelper.Client/Pages/Teacher/StudentsView.razor

@@ -6,7 +6,9 @@
 
 @foreach(var cs in ClassStudents)
 {
-	<MudText> @cs.DisplayName </MudText>
+	<StudentCard StudentDto="@cs">
+	</StudentCard>
+
 }