[Performance] MAL performance test

[wankai123]

When I do envoy metrics analyze the github e2e env (poor resources) collapse time after time because the computer resources run out.
Since each envoy proxy is a sender to sends metrics to OAP, the number of senders and metrics set could be large-scale.

I think we need a performance test for this to identify the different scenarios the pressure of the OAP as well as the computer resources cost.

The different scenarios could be set by:

• The number of the senders(pods/envoy proxy)
• The size of the metrics set
• The number of analyze rules