Implement Discord appeal functionality, including database schema, API endpoints, front-end form, and Discord message handling.

backend/src/main/java/com/alttd/altitudeweb/mappers/BannedUserToBannedUserDtoMapper.java

@@ -0,0 +1,14 @@
+package com.alttd.altitudeweb.mappers;
+
+import com.alttd.altitudeweb.model.BannedUserDto;
+import com.alttd.webinterface.appeals.BannedUser;
+import org.springframework.stereotype.Service;
+
+@Service
+public class BannedUserToBannedUserDtoMapper {
+
+    public BannedUserDto map(BannedUser bannedUser) {
+        return new BannedUserDto(bannedUser.userId(), bannedUser.reason(), bannedUser.name(), bannedUser.avatarUrl());
+    }
+
+}