e2e: add testcases for rate limit annotations

[澄潭]

Why do you need it?

annotations:

• higress.io/route-limit-rps
• higress.io/route-limit-rpm
• higress.io/route-limit-burst-multiplier

How could it be?

see: https://higress.io/zh-cn/docs/user/annotation-use-case#%E5%8D%95%E6%9C%BA%E9%99%90%E6%B5%81

Other related information

• https://github.com/alibaba/higress/tree/main/test
• #190

[dongdongh233]

please assign to me