feat: add network delay scenario and automated test run by tag

[gvelez17]

See ./scenarios/README.md for instructions

Once the cluster is set up, you can just run

python3 exer_image.py 2.37.0-rc.1

to load test the specified js-ceramic image, using a 5-second simulated network delay. The script is a bit hacky but edits the required files and kicks off the load test automatically.

A run looks like this

gv@birdbox scenarios % python3 exer_image.py 2.36.1
Context "gke_box-benchmarking-ipfs-testing_us-central1-c_load-testing-with-network-delays" modified.
network.keramik.3box.io/load-with-delay-for-2-36-1 created
Context "gke_box-benchmarking-ipfs-testing_us-central1-c_load-testing-with-network-delays" modified.
statefulset.apps/cas patched
namespace/keramik-load-with-delay-for-2-36-1 labeled
virtualservice.networking.istio.io/delay-cas created
simulation.keramik.3box.io/ceramic-write-only-simulation created
Running simulation for load-with-delay-for-2-36-1
See https://us3.datadoghq.com/apm/home for results
to clean up in 15 minutes run `kubectl delete -f network-with-cas.html`