chaos_experimentation: squeeze experiments

[Kathan]

Description
When we perform a Squeeze experiment on service, we route additional traffic to a particular host in that service. This helps in determining the maximum number of concurrent requests that can be served by that host in a cluster. After performing the squeeze experiment, one can set the scaling threshold of service as well as the circuit breaking threshold.

To route additional traffic to a host, load balancing needs to be adjusted in a way that the host under experiment gets more weight. This can be achieved with Envoy Proxy's load balancing policies

Complexity [S/M/L]: L