Discuss an Istio Conformance program

[castrojo]

I'd like to help facilitate a conformance program based on what the Istio community is looking to achieve. Brought this up at a prior Istio community meeting and so just opening an issue for tracking purposes. Looking forward to figuring this out together!

Prior work/examples:

• https://github.com/cncf/k8s-conformance
• https://www.cncf.io/certification/software-conformance/

[howardjohn]

There was some discussion of this in steering, currently this doesn't seem to be the right time to add something like this to Istio. There is some possible interest in the future, especially in a scoped context (ambient/gateway API)