feat: implement ApiKeysModule with services, controller, and CRUD operations

Added a dedicated ApiKeysModule to manage API keys. Includes functionality to create, list, revoke, and validate keys, leveraging cryptographic hashing and database support. Integrated with authentication guards for security.

backend/src/api-keys/api-keys.module.ts

@@ -0,0 +1,14 @@
+import { Module } from "@nestjs/common";
+import { AuthModule } from "../auth/auth.module";
+import { CryptoModule } from "../crypto/crypto.module";
+import { DatabaseModule } from "../database/database.module";
+import { ApiKeysController } from "./api-keys.controller";
+import { ApiKeysService } from "./api-keys.service";
+
+@Module({
+	imports: [DatabaseModule, AuthModule, CryptoModule],
+	controllers: [ApiKeysController],
+	providers: [ApiKeysService],
+	exports: [ApiKeysService],
+})
+export class ApiKeysModule {}