feat: add new config strategy to backend

backend/src/config/dto/config.dto.ts

@@ -0,0 +1,18 @@
+import { Expose, plainToClass } from "class-transformer";
+
+export class ConfigDTO {
+  @Expose()
+  key: string;
+
+  @Expose()
+  value: string;
+
+  @Expose()
+  type: string;
+
+  fromList(partial: Partial<ConfigDTO>[]) {
+    return partial.map((part) =>
+      plainToClass(ConfigDTO, part, { excludeExtraneousValues: true })
+    );
+  }
+}