Update SurveyLib and add support for multiple answer questions

SurveyBackend/SurveyBackend.Infrastructure/Data/Migrations/ApplicationDbContextModelSnapshot.cs

@@ -76,20 +76,27 @@ namespace SurveyBackend.Infrastructure.Data.Migrations
 
             modelBuilder.Entity("SurveyLib.Core.Models.Answer", b =>
                 {
-                    b.Property<int>("CompletionId")
-                        .HasColumnType("INTEGER");
-
-                    b.Property<int>("QuestionId")
+                    b.Property<int>("Id")
+                        .ValueGeneratedOnAdd()
                         .HasColumnType("INTEGER");
 
                     b.Property<string>("AnswerText")
                         .IsRequired()
                         .HasColumnType("TEXT");
 
-                    b.HasKey("CompletionId", "QuestionId");
+                    b.Property<int>("CompletionId")
+                        .HasColumnType("INTEGER");
+
+                    b.Property<int>("QuestionId")
+                        .HasColumnType("INTEGER");
+
+                    b.HasKey("Id");
 
                     b.HasIndex("QuestionId");
 
+                    b.HasIndex("CompletionId", "QuestionId", "AnswerText")
+                        .IsUnique();
+
                     b.ToTable("Answers");
                 });