feat: import/export settings, send backup of settings when leaving guild

Catalogger.Backend/Database/Redis/RedisService.cs

@@ -44,6 +44,9 @@ public class RedisService(Config config)
         await GetDatabase().StringSetAsync(key, json, expiry);
     }
 
+    public async Task DeleteAsync(string[] keys) =>
+        await GetDatabase().KeyDeleteAsync(keys.Select(k => new RedisKey(k)).ToArray());
+
     public async Task<T?> GetAsync<T>(string key)
     {
         var value = await GetDatabase().StringGetAsync(key);