Support for temporary http status codes

Use-Case: Someone manually puts an endpoint into some sort of maintenance mode so instead of return a 200 it now returns a 302.

Right now this triggers a status code metric to change for 0 to 1. It would be nice to be able to specify a grace period for this temporary status code.

Another option would be to output a different metric value when the temporary status code is being returned.

This would then be able to not trigger alarms unless the temporary status code remains in-place for greater than grace period

首先跟踪 Lambda 的 HTTP 状态处理和 CloudWatch 指标发送。明确预期行为是可配置的宽限期，还是针对临时状态码使用不同的指标值；完成标准应包括定义配置，并确保临时响应仍处于宽限期内时不会触发告警。

由索引模型根据 Issue 内容生成。